net/core/dev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      NET3    Protocol independent device support routines.
   4  *
   5  *      Derived from the non IP parts of dev.c 1.0.19
   6  *              Authors:        Ross Biro
   7  *                              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   8  *                              Mark Evans, <evansmp@uhura.aston.ac.uk>
   9  *
  10  *      Additional Authors:
  11  *              Florian la Roche <rzsfl@rz.uni-sb.de>
  12  *              Alan Cox <gw4pts@gw4pts.ampr.org>
  13  *              David Hinds <dahinds@users.sourceforge.net>
  14  *              Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
  15  *              Adam Sulmicki <adam@cfar.umd.edu>
  16  *              Pekka Riikonen <priikone@poesidon.pspt.fi>
  17  *
  18  *      Changes:
  19  *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
  20  *                                      to 2 if register_netdev gets called
  21  *                                      before net_dev_init & also removed a
  22  *                                      few lines of code in the process.
  23  *              Alan Cox        :       device private ioctl copies fields back.
  24  *              Alan Cox        :       Transmit queue code does relevant
  25  *                                      stunts to keep the queue safe.
  26  *              Alan Cox        :       Fixed double lock.
  27  *              Alan Cox        :       Fixed promisc NULL pointer trap
  28  *              ????????        :       Support the full private ioctl range
  29  *              Alan Cox        :       Moved ioctl permission check into
  30  *                                      drivers
  31  *              Tim Kordas      :       SIOCADDMULTI/SIOCDELMULTI
  32  *              Alan Cox        :       100 backlog just doesn't cut it when
  33  *                                      you start doing multicast video 8)
  34  *              Alan Cox        :       Rewrote net_bh and list manager.
  35  *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
  36  *              Alan Cox        :       Took out transmit every packet pass
  37  *                                      Saved a few bytes in the ioctl handler
  38  *              Alan Cox        :       Network driver sets packet type before
  39  *                                      calling netif_rx. Saves a function
  40  *                                      call a packet.
  41  *              Alan Cox        :       Hashed net_bh()
  42  *              Richard Kooijman:       Timestamp fixes.
  43  *              Alan Cox        :       Wrong field in SIOCGIFDSTADDR
  44  *              Alan Cox        :       Device lock protection.
  45  *              Alan Cox        :       Fixed nasty side effect of device close
  46  *                                      changes.
  47  *              Rudi Cilibrasi  :       Pass the right thing to
  48  *                                      set_mac_address()
  49  *              Dave Miller     :       32bit quantity for the device lock to
  50  *                                      make it work out on a Sparc.
  51  *              Bjorn Ekwall    :       Added KERNELD hack.
  52  *              Alan Cox        :       Cleaned up the backlog initialise.
  53  *              Craig Metz      :       SIOCGIFCONF fix if space for under
  54  *                                      1 device.
  55  *          Thomas Bogendoerfer :       Return ENODEV for dev_open, if there
  56  *                                      is no device open function.
  57  *              Andi Kleen      :       Fix error reporting for SIOCGIFCONF
  58  *          Michael Chastain    :       Fix signed/unsigned for SIOCGIFCONF
  59  *              Cyrus Durgin    :       Cleaned for KMOD
  60  *              Adam Sulmicki   :       Bug Fix : Network Device Unload
  61  *                                      A network device unload needs to purge
  62  *                                      the backlog queue.
  63  *      Paul Rusty Russell      :       SIOCSIFNAME
  64  *              Pekka Riikonen  :       Netdev boot-time settings code
  65  *              Andrew Morton   :       Make unregister_netdevice wait
  66  *                                      indefinitely on dev->refcnt
  67  *              J Hadi Salim    :       - Backlog queue sampling
  68  *                                      - netif_rx() feedback
  69  */
  70
  71 #include <linux/uaccess.h>
  72 #include <linux/bitops.h>
  73 #include <linux/capability.h>
  74 #include <linux/cpu.h>
  75 #include <linux/types.h>
  76 #include <linux/kernel.h>
  77 #include <linux/hash.h>
  78 #include <linux/slab.h>
  79 #include <linux/sched.h>
  80 #include <linux/sched/mm.h>
  81 #include <linux/mutex.h>
  82 #include <linux/rwsem.h>
  83 #include <linux/string.h>
  84 #include <linux/mm.h>
  85 #include <linux/socket.h>
  86 #include <linux/sockios.h>
  87 #include <linux/errno.h>
  88 #include <linux/interrupt.h>
  89 #include <linux/if_ether.h>
  90 #include <linux/netdevice.h>
  91 #include <linux/etherdevice.h>
  92 #include <linux/ethtool.h>
  93 #include <linux/skbuff.h>
  94 #include <linux/kthread.h>
  95 #include <linux/bpf.h>
  96 #include <linux/bpf_trace.h>
  97 #include <net/net_namespace.h>
  98 #include <net/sock.h>
  99 #include <net/busy_poll.h>
 100 #include <linux/rtnetlink.h>
 101 #include <linux/stat.h>
 102 #include <net/dsa.h>
 103 #include <net/dst.h>
 104 #include <net/dst_metadata.h>
 105 #include <net/gro.h>
 106 #include <net/pkt_sched.h>
 107 #include <net/pkt_cls.h>
 108 #include <net/checksum.h>
 109 #include <net/xfrm.h>
 110 #include <linux/highmem.h>
 111 #include <linux/init.h>
 112 #include <linux/module.h>
 113 #include <linux/netpoll.h>
 114 #include <linux/rcupdate.h>
 115 #include <linux/delay.h>
 116 #include <net/iw_handler.h>
 117 #include <asm/current.h>
 118 #include <linux/audit.h>
 119 #include <linux/dmaengine.h>
 120 #include <linux/err.h>
 121 #include <linux/ctype.h>
 122 #include <linux/if_arp.h>
 123 #include <linux/if_vlan.h>
 124 #include <linux/ip.h>
 125 #include <net/ip.h>
 126 #include <net/mpls.h>
 127 #include <linux/ipv6.h>
 128 #include <linux/in.h>
 129 #include <linux/jhash.h>
 130 #include <linux/random.h>
 131 #include <trace/events/napi.h>
 132 #include <trace/events/net.h>
 133 #include <trace/events/skb.h>
 134 #include <trace/events/qdisc.h>
 135 #include <linux/inetdevice.h>
 136 #include <linux/cpu_rmap.h>
 137 #include <linux/static_key.h>
 138 #include <linux/hashtable.h>
 139 #include <linux/vmalloc.h>
 140 #include <linux/if_macvlan.h>
 141 #include <linux/errqueue.h>
 142 #include <linux/hrtimer.h>
 143 #include <linux/netfilter_netdev.h>
 144 #include <linux/crash_dump.h>
 145 #include <linux/sctp.h>
 146 #include <net/udp_tunnel.h>
 147 #include <linux/net_namespace.h>
 148 #include <linux/indirect_call_wrapper.h>
 149 #include <net/devlink.h>
 150 #include <linux/pm_runtime.h>
 151 #include <linux/prandom.h>
 152 #include <linux/once_lite.h>
 153
 154 #include "net-sysfs.h"
 155
 156
 157 static DEFINE_SPINLOCK(ptype_lock);
 158 struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
 159 struct list_head ptype_all __read_mostly;       /* Taps */
 160
 161 static int netif_rx_internal(struct sk_buff *skb);
 162 static int call_netdevice_notifiers_info(unsigned long val,
 163                                          struct netdev_notifier_info *info);
 164 static int call_netdevice_notifiers_extack(unsigned long val,
 165                                            struct net_device *dev,
 166                                            struct netlink_ext_ack *extack);
 167 static struct napi_struct *napi_by_id(unsigned int napi_id);
 168
 169 /*
 170  * The @dev_base_head list is protected by @dev_base_lock and the rtnl
 171  * semaphore.
 172  *
 173  * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
 174  *
 175  * Writers must hold the rtnl semaphore while they loop through the
 176  * dev_base_head list, and hold dev_base_lock for writing when they do the
 177  * actual updates.  This allows pure readers to access the list even
 178  * while a writer is preparing to update it.
 179  *
 180  * To put it another way, dev_base_lock is held for writing only to
 181  * protect against pure readers; the rtnl semaphore provides the
 182  * protection against other writers.
 183  *
 184  * See, for example usages, register_netdevice() and
 185  * unregister_netdevice(), which must be called with the rtnl
 186  * semaphore held.
 187  */
 188 DEFINE_RWLOCK(dev_base_lock);
 189 EXPORT_SYMBOL(dev_base_lock);
 190
 191 static DEFINE_MUTEX(ifalias_mutex);
 192
 193 /* protects napi_hash addition/deletion and napi_gen_id */
 194 static DEFINE_SPINLOCK(napi_hash_lock);
 195
 196 static unsigned int napi_gen_id = NR_CPUS;
 197 static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
 198
 199 static DECLARE_RWSEM(devnet_rename_sem);
 200
 201 static inline void dev_base_seq_inc(struct net *net)
 202 {
 203         while (++net->dev_base_seq == 0)
 204                 ;
 205 }
 206
 207 static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
 208 {
 209         unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
 210
 211         return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
 212 }
 213
 214 static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
 215 {
 216         return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
 217 }
 218
 219 static inline void rps_lock_irqsave(struct softnet_data *sd,
 220                                     unsigned long *flags)
 221 {
 222         if (IS_ENABLED(CONFIG_RPS))
 223                 spin_lock_irqsave(&sd->input_pkt_queue.lock, *flags);
 224         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 225                 local_irq_save(*flags);
 226 }
 227
 228 static inline void rps_lock_irq_disable(struct softnet_data *sd)
 229 {
 230         if (IS_ENABLED(CONFIG_RPS))
 231                 spin_lock_irq(&sd->input_pkt_queue.lock);
 232         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 233                 local_irq_disable();
 234 }
 235
 236 static inline void rps_unlock_irq_restore(struct softnet_data *sd,
 237                                           unsigned long *flags)
 238 {
 239         if (IS_ENABLED(CONFIG_RPS))
 240                 spin_unlock_irqrestore(&sd->input_pkt_queue.lock, *flags);
 241         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 242                 local_irq_restore(*flags);
 243 }
 244
 245 static inline void rps_unlock_irq_enable(struct softnet_data *sd)
 246 {
 247         if (IS_ENABLED(CONFIG_RPS))
 248                 spin_unlock_irq(&sd->input_pkt_queue.lock);
 249         else if (!IS_ENABLED(CONFIG_PREEMPT_RT))
 250                 local_irq_enable();
 251 }
 252
 253 static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
 254                                                        const char *name)
 255 {
 256         struct netdev_name_node *name_node;
 257
 258         name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
 259         if (!name_node)
 260                 return NULL;
 261         INIT_HLIST_NODE(&name_node->hlist);
 262         name_node->dev = dev;
 263         name_node->name = name;
 264         return name_node;
 265 }
 266
 267 static struct netdev_name_node *
 268 netdev_name_node_head_alloc(struct net_device *dev)
 269 {
 270         struct netdev_name_node *name_node;
 271
 272         name_node = netdev_name_node_alloc(dev, dev->name);
 273         if (!name_node)
 274                 return NULL;
 275         INIT_LIST_HEAD(&name_node->list);
 276         return name_node;
 277 }
 278
 279 static void netdev_name_node_free(struct netdev_name_node *name_node)
 280 {
 281         kfree(name_node);
 282 }
 283
 284 static void netdev_name_node_add(struct net *net,
 285                                  struct netdev_name_node *name_node)
 286 {
 287         hlist_add_head_rcu(&name_node->hlist,
 288                            dev_name_hash(net, name_node->name));
 289 }
 290
 291 static void netdev_name_node_del(struct netdev_name_node *name_node)
 292 {
 293         hlist_del_rcu(&name_node->hlist);
 294 }
 295
 296 static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
 297                                                         const char *name)
 298 {
 299         struct hlist_head *head = dev_name_hash(net, name);
 300         struct netdev_name_node *name_node;
 301
 302         hlist_for_each_entry(name_node, head, hlist)
 303                 if (!strcmp(name_node->name, name))
 304                         return name_node;
 305         return NULL;
 306 }
 307
 308 static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
 309                                                             const char *name)
 310 {
 311         struct hlist_head *head = dev_name_hash(net, name);
 312         struct netdev_name_node *name_node;
 313
 314         hlist_for_each_entry_rcu(name_node, head, hlist)
 315                 if (!strcmp(name_node->name, name))
 316                         return name_node;
 317         return NULL;
 318 }
 319
 320 bool netdev_name_in_use(struct net *net, const char *name)
 321 {
 322         return netdev_name_node_lookup(net, name);
 323 }
 324 EXPORT_SYMBOL(netdev_name_in_use);
 325
 326 int netdev_name_node_alt_create(struct net_device *dev, const char *name)
 327 {
 328         struct netdev_name_node *name_node;
 329         struct net *net = dev_net(dev);
 330
 331         name_node = netdev_name_node_lookup(net, name);
 332         if (name_node)
 333                 return -EEXIST;
 334         name_node = netdev_name_node_alloc(dev, name);
 335         if (!name_node)
 336                 return -ENOMEM;
 337         netdev_name_node_add(net, name_node);
 338         /* The node that holds dev->name acts as a head of per-device list. */
 339         list_add_tail(&name_node->list, &dev->name_node->list);
 340
 341         return 0;
 342 }
 343
 344 static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
 345 {
 346         list_del(&name_node->list);
 347         netdev_name_node_del(name_node);
 348         kfree(name_node->name);
 349         netdev_name_node_free(name_node);
 350 }
 351
 352 int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
 353 {
 354         struct netdev_name_node *name_node;
 355         struct net *net = dev_net(dev);
 356
 357         name_node = netdev_name_node_lookup(net, name);
 358         if (!name_node)
 359                 return -ENOENT;
 360         /* lookup might have found our primary name or a name belonging
 361          * to another device.
 362          */
 363         if (name_node == dev->name_node || name_node->dev != dev)
 364                 return -EINVAL;
 365
 366         __netdev_name_node_alt_destroy(name_node);
 367
 368         return 0;
 369 }
 370
 371 static void netdev_name_node_alt_flush(struct net_device *dev)
 372 {
 373         struct netdev_name_node *name_node, *tmp;
 374
 375         list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
 376                 __netdev_name_node_alt_destroy(name_node);
 377 }
 378
 379 /* Device list insertion */
 380 static void list_netdevice(struct net_device *dev)
 381 {
 382         struct net *net = dev_net(dev);
 383
 384         ASSERT_RTNL();
 385
 386         write_lock(&dev_base_lock);
 387         list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
 388         netdev_name_node_add(net, dev->name_node);
 389         hlist_add_head_rcu(&dev->index_hlist,
 390                            dev_index_hash(net, dev->ifindex));
 391         write_unlock(&dev_base_lock);
 392
 393         dev_base_seq_inc(net);
 394 }
 395
 396 /* Device list removal
 397  * caller must respect a RCU grace period before freeing/reusing dev
 398  */
 399 static void unlist_netdevice(struct net_device *dev)
 400 {
 401         ASSERT_RTNL();
 402
 403         /* Unlink dev from the device chain */
 404         write_lock(&dev_base_lock);
 405         list_del_rcu(&dev->dev_list);
 406         netdev_name_node_del(dev->name_node);
 407         hlist_del_rcu(&dev->index_hlist);
 408         write_unlock(&dev_base_lock);
 409
 410         dev_base_seq_inc(dev_net(dev));
 411 }
 412
 413 /*
 414  *      Our notifier list
 415  */
 416
 417 static RAW_NOTIFIER_HEAD(netdev_chain);
 418
 419 /*
 420  *      Device drivers call our routines to queue packets here. We empty the
 421  *      queue in the local softnet handler.
 422  */
 423
 424 DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
 425 EXPORT_PER_CPU_SYMBOL(softnet_data);
 426
 427 #ifdef CONFIG_LOCKDEP
 428 /*
 429  * register_netdevice() inits txq->_xmit_lock and sets lockdep class
 430  * according to dev->type
 431  */
 432 static const unsigned short netdev_lock_type[] = {
 433          ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
 434          ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
 435          ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
 436          ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
 437          ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
 438          ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
 439          ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
 440          ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
 441          ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
 442          ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
 443          ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
 444          ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
 445          ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
 446          ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
 447          ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
 448
 449 static const char *const netdev_lock_name[] = {
 450         "_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
 451         "_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
 452         "_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
 453         "_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
 454         "_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
 455         "_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
 456         "_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
 457         "_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
 458         "_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
 459         "_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
 460         "_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
 461         "_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
 462         "_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
 463         "_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
 464         "_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
 465
 466 static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
 467 static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
 468
 469 static inline unsigned short netdev_lock_pos(unsigned short dev_type)
 470 {
 471         int i;
 472
 473         for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
 474                 if (netdev_lock_type[i] == dev_type)
 475                         return i;
 476         /* the last key is used by default */
 477         return ARRAY_SIZE(netdev_lock_type) - 1;
 478 }
 479
 480 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
 481                                                  unsigned short dev_type)
 482 {
 483         int i;
 484
 485         i = netdev_lock_pos(dev_type);
 486         lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
 487                                    netdev_lock_name[i]);
 488 }
 489
 490 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 491 {
 492         int i;
 493
 494         i = netdev_lock_pos(dev->type);
 495         lockdep_set_class_and_name(&dev->addr_list_lock,
 496                                    &netdev_addr_lock_key[i],
 497                                    netdev_lock_name[i]);
 498 }
 499 #else
 500 static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
 501                                                  unsigned short dev_type)
 502 {
 503 }
 504
 505 static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
 506 {
 507 }
 508 #endif
 509
 510 /*******************************************************************************
 511  *
 512  *              Protocol management and registration routines
 513  *
 514  *******************************************************************************/
 515
 516
 517 /*
 518  *      Add a protocol ID to the list. Now that the input handler is
 519  *      smarter we can dispense with all the messy stuff that used to be
 520  *      here.
 521  *
 522  *      BEWARE!!! Protocol handlers, mangling input packets,
 523  *      MUST BE last in hash buckets and checking protocol handlers
 524  *      MUST start from promiscuous ptype_all chain in net_bh.
 525  *      It is true now, do not change it.
 526  *      Explanation follows: if protocol handler, mangling packet, will
 527  *      be the first on list, it is not able to sense, that packet
 528  *      is cloned and should be copied-on-write, so that it will
 529  *      change it and subsequent readers will get broken packet.
 530  *                                                      --ANK (980803)
 531  */
 532
 533 static inline struct list_head *ptype_head(const struct packet_type *pt)
 534 {
 535         if (pt->type == htons(ETH_P_ALL))
 536                 return pt->dev ? &pt->dev->ptype_all : &ptype_all;
 537         else
 538                 return pt->dev ? &pt->dev->ptype_specific :
 539                                  &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
 540 }
 541
 542 /**
 543  *      dev_add_pack - add packet handler
 544  *      @pt: packet type declaration
 545  *
 546  *      Add a protocol handler to the networking stack. The passed &packet_type
 547  *      is linked into kernel lists and may not be freed until it has been
 548  *      removed from the kernel lists.
 549  *
 550  *      This call does not sleep therefore it can not
 551  *      guarantee all CPU's that are in middle of receiving packets
 552  *      will see the new packet type (until the next received packet).
 553  */
 554
 555 void dev_add_pack(struct packet_type *pt)
 556 {
 557         struct list_head *head = ptype_head(pt);
 558
 559         spin_lock(&ptype_lock);
 560         list_add_rcu(&pt->list, head);
 561         spin_unlock(&ptype_lock);
 562 }
 563 EXPORT_SYMBOL(dev_add_pack);
 564
 565 /**
 566  *      __dev_remove_pack        - remove packet handler
 567  *      @pt: packet type declaration
 568  *
 569  *      Remove a protocol handler that was previously added to the kernel
 570  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
 571  *      from the kernel lists and can be freed or reused once this function
 572  *      returns.
 573  *
 574  *      The packet type might still be in use by receivers
 575  *      and must not be freed until after all the CPU's have gone
 576  *      through a quiescent state.
 577  */
 578 void __dev_remove_pack(struct packet_type *pt)
 579 {
 580         struct list_head *head = ptype_head(pt);
 581         struct packet_type *pt1;
 582
 583         spin_lock(&ptype_lock);
 584
 585         list_for_each_entry(pt1, head, list) {
 586                 if (pt == pt1) {
 587                         list_del_rcu(&pt->list);
 588                         goto out;
 589                 }
 590         }
 591
 592         pr_warn("dev_remove_pack: %p not found\n", pt);
 593 out:
 594         spin_unlock(&ptype_lock);
 595 }
 596 EXPORT_SYMBOL(__dev_remove_pack);
 597
 598 /**
 599  *      dev_remove_pack  - remove packet handler
 600  *      @pt: packet type declaration
 601  *
 602  *      Remove a protocol handler that was previously added to the kernel
 603  *      protocol handlers by dev_add_pack(). The passed &packet_type is removed
 604  *      from the kernel lists and can be freed or reused once this function
 605  *      returns.
 606  *
 607  *      This call sleeps to guarantee that no CPU is looking at the packet
 608  *      type after return.
 609  */
 610 void dev_remove_pack(struct packet_type *pt)
 611 {
 612         __dev_remove_pack(pt);
 613
 614         synchronize_net();
 615 }
 616 EXPORT_SYMBOL(dev_remove_pack);
 617
 618
 619 /*******************************************************************************
 620  *
 621  *                          Device Interface Subroutines
 622  *
 623  *******************************************************************************/
 624
 625 /**
 626  *      dev_get_iflink  - get 'iflink' value of a interface
 627  *      @dev: targeted interface
 628  *
 629  *      Indicates the ifindex the interface is linked to.
 630  *      Physical interfaces have the same 'ifindex' and 'iflink' values.
 631  */
 632
 633 int dev_get_iflink(const struct net_device *dev)
 634 {
 635         if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
 636                 return dev->netdev_ops->ndo_get_iflink(dev);
 637
 638         return dev->ifindex;
 639 }
 640 EXPORT_SYMBOL(dev_get_iflink);
 641
 642 /**
 643  *      dev_fill_metadata_dst - Retrieve tunnel egress information.
 644  *      @dev: targeted interface
 645  *      @skb: The packet.
 646  *
 647  *      For better visibility of tunnel traffic OVS needs to retrieve
 648  *      egress tunnel information for a packet. Following API allows
 649  *      user to get this info.
 650  */
 651 int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
 652 {
 653         struct ip_tunnel_info *info;
 654
 655         if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
 656                 return -EINVAL;
 657
 658         info = skb_tunnel_info_unclone(skb);
 659         if (!info)
 660                 return -ENOMEM;
 661         if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
 662                 return -EINVAL;
 663
 664         return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
 665 }
 666 EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
 667
 668 static struct net_device_path *dev_fwd_path(struct net_device_path_stack *stack)
 669 {
 670         int k = stack->num_paths++;
 671
 672         if (WARN_ON_ONCE(k >= NET_DEVICE_PATH_STACK_MAX))
 673                 return NULL;
 674
 675         return &stack->path[k];
 676 }
 677
 678 int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
 679                           struct net_device_path_stack *stack)
 680 {
 681         const struct net_device *last_dev;
 682         struct net_device_path_ctx ctx = {
 683                 .dev    = dev,
 684                 .daddr  = daddr,
 685         };
 686         struct net_device_path *path;
 687         int ret = 0;
 688
 689         stack->num_paths = 0;
 690         while (ctx.dev && ctx.dev->netdev_ops->ndo_fill_forward_path) {
 691                 last_dev = ctx.dev;
 692                 path = dev_fwd_path(stack);
 693                 if (!path)
 694                         return -1;
 695
 696                 memset(path, 0, sizeof(struct net_device_path));
 697                 ret = ctx.dev->netdev_ops->ndo_fill_forward_path(&ctx, path);
 698                 if (ret < 0)
 699                         return -1;
 700
 701                 if (WARN_ON_ONCE(last_dev == ctx.dev))
 702                         return -1;
 703         }
 704         path = dev_fwd_path(stack);
 705         if (!path)
 706                 return -1;
 707         path->type = DEV_PATH_ETHERNET;
 708         path->dev = ctx.dev;
 709
 710         return ret;
 711 }
 712 EXPORT_SYMBOL_GPL(dev_fill_forward_path);
 713
 714 /**
 715  *      __dev_get_by_name       - find a device by its name
 716  *      @net: the applicable net namespace
 717  *      @name: name to find
 718  *
 719  *      Find an interface by name. Must be called under RTNL semaphore
 720  *      or @dev_base_lock. If the name is found a pointer to the device
 721  *      is returned. If the name is not found then %NULL is returned. The
 722  *      reference counters are not incremented so the caller must be
 723  *      careful with locks.
 724  */
 725
 726 struct net_device *__dev_get_by_name(struct net *net, const char *name)
 727 {
 728         struct netdev_name_node *node_name;
 729
 730         node_name = netdev_name_node_lookup(net, name);
 731         return node_name ? node_name->dev : NULL;
 732 }
 733 EXPORT_SYMBOL(__dev_get_by_name);
 734
 735 /**
 736  * dev_get_by_name_rcu  - find a device by its name
 737  * @net: the applicable net namespace
 738  * @name: name to find
 739  *
 740  * Find an interface by name.
 741  * If the name is found a pointer to the device is returned.
 742  * If the name is not found then %NULL is returned.
 743  * The reference counters are not incremented so the caller must be
 744  * careful with locks. The caller must hold RCU lock.
 745  */
 746
 747 struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
 748 {
 749         struct netdev_name_node *node_name;
 750
 751         node_name = netdev_name_node_lookup_rcu(net, name);
 752         return node_name ? node_name->dev : NULL;
 753 }
 754 EXPORT_SYMBOL(dev_get_by_name_rcu);
 755
 756 /**
 757  *      dev_get_by_name         - find a device by its name
 758  *      @net: the applicable net namespace
 759  *      @name: name to find
 760  *
 761  *      Find an interface by name. This can be called from any
 762  *      context and does its own locking. The returned handle has
 763  *      the usage count incremented and the caller must use dev_put() to
 764  *      release it when it is no longer needed. %NULL is returned if no
 765  *      matching device is found.
 766  */
 767
 768 struct net_device *dev_get_by_name(struct net *net, const char *name)
 769 {
 770         struct net_device *dev;
 771
 772         rcu_read_lock();
 773         dev = dev_get_by_name_rcu(net, name);
 774         dev_hold(dev);
 775         rcu_read_unlock();
 776         return dev;
 777 }
 778 EXPORT_SYMBOL(dev_get_by_name);
 779
 780 /**
 781  *      __dev_get_by_index - find a device by its ifindex
 782  *      @net: the applicable net namespace
 783  *      @ifindex: index of device
 784  *
 785  *      Search for an interface by index. Returns %NULL if the device
 786  *      is not found or a pointer to the device. The device has not
 787  *      had its reference counter increased so the caller must be careful
 788  *      about locking. The caller must hold either the RTNL semaphore
 789  *      or @dev_base_lock.
 790  */
 791
 792 struct net_device *__dev_get_by_index(struct net *net, int ifindex)
 793 {
 794         struct net_device *dev;
 795         struct hlist_head *head = dev_index_hash(net, ifindex);
 796
 797         hlist_for_each_entry(dev, head, index_hlist)
 798                 if (dev->ifindex == ifindex)
 799                         return dev;
 800
 801         return NULL;
 802 }
 803 EXPORT_SYMBOL(__dev_get_by_index);
 804
 805 /**
 806  *      dev_get_by_index_rcu - find a device by its ifindex
 807  *      @net: the applicable net namespace
 808  *      @ifindex: index of device
 809  *
 810  *      Search for an interface by index. Returns %NULL if the device
 811  *      is not found or a pointer to the device. The device has not
 812  *      had its reference counter increased so the caller must be careful
 813  *      about locking. The caller must hold RCU lock.
 814  */
 815
 816 struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
 817 {
 818         struct net_device *dev;
 819         struct hlist_head *head = dev_index_hash(net, ifindex);
 820
 821         hlist_for_each_entry_rcu(dev, head, index_hlist)
 822                 if (dev->ifindex == ifindex)
 823                         return dev;
 824
 825         return NULL;
 826 }
 827 EXPORT_SYMBOL(dev_get_by_index_rcu);
 828
 829
 830 /**
 831  *      dev_get_by_index - find a device by its ifindex
 832  *      @net: the applicable net namespace
 833  *      @ifindex: index of device
 834  *
 835  *      Search for an interface by index. Returns NULL if the device
 836  *      is not found or a pointer to the device. The device returned has
 837  *      had a reference added and the pointer is safe until the user calls
 838  *      dev_put to indicate they have finished with it.
 839  */
 840
 841 struct net_device *dev_get_by_index(struct net *net, int ifindex)
 842 {
 843         struct net_device *dev;
 844
 845         rcu_read_lock();
 846         dev = dev_get_by_index_rcu(net, ifindex);
 847         dev_hold(dev);
 848         rcu_read_unlock();
 849         return dev;
 850 }
 851 EXPORT_SYMBOL(dev_get_by_index);
 852
 853 /**
 854  *      dev_get_by_napi_id - find a device by napi_id
 855  *      @napi_id: ID of the NAPI struct
 856  *
 857  *      Search for an interface by NAPI ID. Returns %NULL if the device
 858  *      is not found or a pointer to the device. The device has not had
 859  *      its reference counter increased so the caller must be careful
 860  *      about locking. The caller must hold RCU lock.
 861  */
 862
 863 struct net_device *dev_get_by_napi_id(unsigned int napi_id)
 864 {
 865         struct napi_struct *napi;
 866
 867         WARN_ON_ONCE(!rcu_read_lock_held());
 868
 869         if (napi_id < MIN_NAPI_ID)
 870                 return NULL;
 871
 872         napi = napi_by_id(napi_id);
 873
 874         return napi ? napi->dev : NULL;
 875 }
 876 EXPORT_SYMBOL(dev_get_by_napi_id);
 877
 878 /**
 879  *      netdev_get_name - get a netdevice name, knowing its ifindex.
 880  *      @net: network namespace
 881  *      @name: a pointer to the buffer where the name will be stored.
 882  *      @ifindex: the ifindex of the interface to get the name from.
 883  */
 884 int netdev_get_name(struct net *net, char *name, int ifindex)
 885 {
 886         struct net_device *dev;
 887         int ret;
 888
 889         down_read(&devnet_rename_sem);
 890         rcu_read_lock();
 891
 892         dev = dev_get_by_index_rcu(net, ifindex);
 893         if (!dev) {
 894                 ret = -ENODEV;
 895                 goto out;
 896         }
 897
 898         strcpy(name, dev->name);
 899
 900         ret = 0;
 901 out:
 902         rcu_read_unlock();
 903         up_read(&devnet_rename_sem);
 904         return ret;
 905 }
 906
 907 /**
 908  *      dev_getbyhwaddr_rcu - find a device by its hardware address
 909  *      @net: the applicable net namespace
 910  *      @type: media type of device
 911  *      @ha: hardware address
 912  *
 913  *      Search for an interface by MAC address. Returns NULL if the device
 914  *      is not found or a pointer to the device.
 915  *      The caller must hold RCU or RTNL.
 916  *      The returned device has not had its ref count increased
 917  *      and the caller must therefore be careful about locking
 918  *
 919  */
 920
 921 struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
 922                                        const char *ha)
 923 {
 924         struct net_device *dev;
 925
 926         for_each_netdev_rcu(net, dev)
 927                 if (dev->type == type &&
 928                     !memcmp(dev->dev_addr, ha, dev->addr_len))
 929                         return dev;
 930
 931         return NULL;
 932 }
 933 EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
 934
 935 struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
 936 {
 937         struct net_device *dev, *ret = NULL;
 938
 939         rcu_read_lock();
 940         for_each_netdev_rcu(net, dev)
 941                 if (dev->type == type) {
 942                         dev_hold(dev);
 943                         ret = dev;
 944                         break;
 945                 }
 946         rcu_read_unlock();
 947         return ret;
 948 }
 949 EXPORT_SYMBOL(dev_getfirstbyhwtype);
 950
 951 /**
 952  *      __dev_get_by_flags - find any device with given flags
 953  *      @net: the applicable net namespace
 954  *      @if_flags: IFF_* values
 955  *      @mask: bitmask of bits in if_flags to check
 956  *
 957  *      Search for any interface with the given flags. Returns NULL if a device
 958  *      is not found or a pointer to the device. Must be called inside
 959  *      rtnl_lock(), and result refcount is unchanged.
 960  */
 961
 962 struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
 963                                       unsigned short mask)
 964 {
 965         struct net_device *dev, *ret;
 966
 967         ASSERT_RTNL();
 968
 969         ret = NULL;
 970         for_each_netdev(net, dev) {
 971                 if (((dev->flags ^ if_flags) & mask) == 0) {
 972                         ret = dev;
 973                         break;
 974                 }
 975         }
 976         return ret;
 977 }
 978 EXPORT_SYMBOL(__dev_get_by_flags);
 979
 980 /**
 981  *      dev_valid_name - check if name is okay for network device
 982  *      @name: name string
 983  *
 984  *      Network device names need to be valid file names to
 985  *      allow sysfs to work.  We also disallow any kind of
 986  *      whitespace.
 987  */
 988 bool dev_valid_name(const char *name)
 989 {
 990         if (*name == '\0')
 991                 return false;
 992         if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
 993                 return false;
 994         if (!strcmp(name, ".") || !strcmp(name, ".."))
 995                 return false;
 996
 997         while (*name) {
 998                 if (*name == '/' || *name == ':' || isspace(*name))
 999                         return false;
1000                 name++;
1001         }
1002         return true;
1003 }
1004 EXPORT_SYMBOL(dev_valid_name);
1005
1006 /**
1007  *      __dev_alloc_name - allocate a name for a device
1008  *      @net: network namespace to allocate the device name in
1009  *      @name: name format string
1010  *      @buf:  scratch buffer and result name string
1011  *
1012  *      Passed a format string - eg "lt%d" it will try and find a suitable
1013  *      id. It scans list of devices to build up a free map, then chooses
1014  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1015  *      while allocating the name and adding the device in order to avoid
1016  *      duplicates.
1017  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1018  *      Returns the number of the unit assigned or a negative errno code.
1019  */
1020
1021 static int __dev_alloc_name(struct net *net, const char *name, char *buf)
1022 {
1023         int i = 0;
1024         const char *p;
1025         const int max_netdevices = 8*PAGE_SIZE;
1026         unsigned long *inuse;
1027         struct net_device *d;
1028
1029         if (!dev_valid_name(name))
1030                 return -EINVAL;
1031
1032         p = strchr(name, '%');
1033         if (p) {
1034                 /*
1035                  * Verify the string as this thing may have come from
1036                  * the user.  There must be either one "%d" and no other "%"
1037                  * characters.
1038                  */
1039                 if (p[1] != 'd' || strchr(p + 2, '%'))
1040                         return -EINVAL;
1041
1042                 /* Use one page as a bit array of possible slots */
1043                 inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
1044                 if (!inuse)
1045                         return -ENOMEM;
1046
1047                 for_each_netdev(net, d) {
1048                         struct netdev_name_node *name_node;
1049                         list_for_each_entry(name_node, &d->name_node->list, list) {
1050                                 if (!sscanf(name_node->name, name, &i))
1051                                         continue;
1052                                 if (i < 0 || i >= max_netdevices)
1053                                         continue;
1054
1055                                 /*  avoid cases where sscanf is not exact inverse of printf */
1056                                 snprintf(buf, IFNAMSIZ, name, i);
1057                                 if (!strncmp(buf, name_node->name, IFNAMSIZ))
1058                                         __set_bit(i, inuse);
1059                         }
1060                         if (!sscanf(d->name, name, &i))
1061                                 continue;
1062                         if (i < 0 || i >= max_netdevices)
1063                                 continue;
1064
1065                         /*  avoid cases where sscanf is not exact inverse of printf */
1066                         snprintf(buf, IFNAMSIZ, name, i);
1067                         if (!strncmp(buf, d->name, IFNAMSIZ))
1068                                 __set_bit(i, inuse);
1069                 }
1070
1071                 i = find_first_zero_bit(inuse, max_netdevices);
1072                 free_page((unsigned long) inuse);
1073         }
1074
1075         snprintf(buf, IFNAMSIZ, name, i);
1076         if (!netdev_name_in_use(net, buf))
1077                 return i;
1078
1079         /* It is possible to run out of possible slots
1080          * when the name is long and there isn't enough space left
1081          * for the digits, or if all bits are used.
1082          */
1083         return -ENFILE;
1084 }
1085
1086 static int dev_alloc_name_ns(struct net *net,
1087                              struct net_device *dev,
1088                              const char *name)
1089 {
1090         char buf[IFNAMSIZ];
1091         int ret;
1092
1093         BUG_ON(!net);
1094         ret = __dev_alloc_name(net, name, buf);
1095         if (ret >= 0)
1096                 strlcpy(dev->name, buf, IFNAMSIZ);
1097         return ret;
1098 }
1099
1100 /**
1101  *      dev_alloc_name - allocate a name for a device
1102  *      @dev: device
1103  *      @name: name format string
1104  *
1105  *      Passed a format string - eg "lt%d" it will try and find a suitable
1106  *      id. It scans list of devices to build up a free map, then chooses
1107  *      the first empty slot. The caller must hold the dev_base or rtnl lock
1108  *      while allocating the name and adding the device in order to avoid
1109  *      duplicates.
1110  *      Limited to bits_per_byte * page size devices (ie 32K on most platforms).
1111  *      Returns the number of the unit assigned or a negative errno code.
1112  */
1113
1114 int dev_alloc_name(struct net_device *dev, const char *name)
1115 {
1116         return dev_alloc_name_ns(dev_net(dev), dev, name);
1117 }
1118 EXPORT_SYMBOL(dev_alloc_name);
1119
1120 static int dev_get_valid_name(struct net *net, struct net_device *dev,
1121                               const char *name)
1122 {
1123         BUG_ON(!net);
1124
1125         if (!dev_valid_name(name))
1126                 return -EINVAL;
1127
1128         if (strchr(name, '%'))
1129                 return dev_alloc_name_ns(net, dev, name);
1130         else if (netdev_name_in_use(net, name))
1131                 return -EEXIST;
1132         else if (dev->name != name)
1133                 strlcpy(dev->name, name, IFNAMSIZ);
1134
1135         return 0;
1136 }
1137
1138 /**
1139  *      dev_change_name - change name of a device
1140  *      @dev: device
1141  *      @newname: name (or format string) must be at least IFNAMSIZ
1142  *
1143  *      Change name of a device, can pass format strings "eth%d".
1144  *      for wildcarding.
1145  */
1146 int dev_change_name(struct net_device *dev, const char *newname)
1147 {
1148         unsigned char old_assign_type;
1149         char oldname[IFNAMSIZ];
1150         int err = 0;
1151         int ret;
1152         struct net *net;
1153
1154         ASSERT_RTNL();
1155         BUG_ON(!dev_net(dev));
1156
1157         net = dev_net(dev);
1158
1159         /* Some auto-enslaved devices e.g. failover slaves are
1160          * special, as userspace might rename the device after
1161          * the interface had been brought up and running since
1162          * the point kernel initiated auto-enslavement. Allow
1163          * live name change even when these slave devices are
1164          * up and running.
1165          *
1166          * Typically, users of these auto-enslaving devices
1167          * don't actually care about slave name change, as
1168          * they are supposed to operate on master interface
1169          * directly.
1170          */
1171         if (dev->flags & IFF_UP &&
1172             likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK)))
1173                 return -EBUSY;
1174
1175         down_write(&devnet_rename_sem);
1176
1177         if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
1178                 up_write(&devnet_rename_sem);
1179                 return 0;
1180         }
1181
1182         memcpy(oldname, dev->name, IFNAMSIZ);
1183
1184         err = dev_get_valid_name(net, dev, newname);
1185         if (err < 0) {
1186                 up_write(&devnet_rename_sem);
1187                 return err;
1188         }
1189
1190         if (oldname[0] && !strchr(oldname, '%'))
1191                 netdev_info(dev, "renamed from %s\n", oldname);
1192
1193         old_assign_type = dev->name_assign_type;
1194         dev->name_assign_type = NET_NAME_RENAMED;
1195
1196 rollback:
1197         ret = device_rename(&dev->dev, dev->name);
1198         if (ret) {
1199                 memcpy(dev->name, oldname, IFNAMSIZ);
1200                 dev->name_assign_type = old_assign_type;
1201                 up_write(&devnet_rename_sem);
1202                 return ret;
1203         }
1204
1205         up_write(&devnet_rename_sem);
1206
1207         netdev_adjacent_rename_links(dev, oldname);
1208
1209         write_lock(&dev_base_lock);
1210         netdev_name_node_del(dev->name_node);
1211         write_unlock(&dev_base_lock);
1212
1213         synchronize_rcu();
1214
1215         write_lock(&dev_base_lock);
1216         netdev_name_node_add(net, dev->name_node);
1217         write_unlock(&dev_base_lock);
1218
1219         ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
1220         ret = notifier_to_errno(ret);
1221
1222         if (ret) {
1223                 /* err >= 0 after dev_alloc_name() or stores the first errno */
1224                 if (err >= 0) {
1225                         err = ret;
1226                         down_write(&devnet_rename_sem);
1227                         memcpy(dev->name, oldname, IFNAMSIZ);
1228                         memcpy(oldname, newname, IFNAMSIZ);
1229                         dev->name_assign_type = old_assign_type;
1230                         old_assign_type = NET_NAME_RENAMED;
1231                         goto rollback;
1232                 } else {
1233                         netdev_err(dev, "name change rollback failed: %d\n",
1234                                    ret);
1235                 }
1236         }
1237
1238         return err;
1239 }
1240
1241 /**
1242  *      dev_set_alias - change ifalias of a device
1243  *      @dev: device
1244  *      @alias: name up to IFALIASZ
1245  *      @len: limit of bytes to copy from info
1246  *
1247  *      Set ifalias for a device,
1248  */
1249 int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
1250 {
1251         struct dev_ifalias *new_alias = NULL;
1252
1253         if (len >= IFALIASZ)
1254                 return -EINVAL;
1255
1256         if (len) {
1257                 new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
1258                 if (!new_alias)
1259                         return -ENOMEM;
1260
1261                 memcpy(new_alias->ifalias, alias, len);
1262                 new_alias->ifalias[len] = 0;
1263         }
1264
1265         mutex_lock(&ifalias_mutex);
1266         new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
1267                                         mutex_is_locked(&ifalias_mutex));
1268         mutex_unlock(&ifalias_mutex);
1269
1270         if (new_alias)
1271                 kfree_rcu(new_alias, rcuhead);
1272
1273         return len;
1274 }
1275 EXPORT_SYMBOL(dev_set_alias);
1276
1277 /**
1278  *      dev_get_alias - get ifalias of a device
1279  *      @dev: device
1280  *      @name: buffer to store name of ifalias
1281  *      @len: size of buffer
1282  *
1283  *      get ifalias for a device.  Caller must make sure dev cannot go
1284  *      away,  e.g. rcu read lock or own a reference count to device.
1285  */
1286 int dev_get_alias(const struct net_device *dev, char *name, size_t len)
1287 {
1288         const struct dev_ifalias *alias;
1289         int ret = 0;
1290
1291         rcu_read_lock();
1292         alias = rcu_dereference(dev->ifalias);
1293         if (alias)
1294                 ret = snprintf(name, len, "%s", alias->ifalias);
1295         rcu_read_unlock();
1296
1297         return ret;
1298 }
1299
1300 /**
1301  *      netdev_features_change - device changes features
1302  *      @dev: device to cause notification
1303  *
1304  *      Called to indicate a device has changed features.
1305  */
1306 void netdev_features_change(struct net_device *dev)
1307 {
1308         call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
1309 }
1310 EXPORT_SYMBOL(netdev_features_change);
1311
1312 /**
1313  *      netdev_state_change - device changes state
1314  *      @dev: device to cause notification
1315  *
1316  *      Called to indicate a device has changed state. This function calls
1317  *      the notifier chains for netdev_chain and sends a NEWLINK message
1318  *      to the routing socket.
1319  */
1320 void netdev_state_change(struct net_device *dev)
1321 {
1322         if (dev->flags & IFF_UP) {
1323                 struct netdev_notifier_change_info change_info = {
1324                         .info.dev = dev,
1325                 };
1326
1327                 call_netdevice_notifiers_info(NETDEV_CHANGE,
1328                                               &change_info.info);
1329                 rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
1330         }
1331 }
1332 EXPORT_SYMBOL(netdev_state_change);
1333
1334 /**
1335  * __netdev_notify_peers - notify network peers about existence of @dev,
1336  * to be called when rtnl lock is already held.
1337  * @dev: network device
1338  *
1339  * Generate traffic such that interested network peers are aware of
1340  * @dev, such as by generating a gratuitous ARP. This may be used when
1341  * a device wants to inform the rest of the network about some sort of
1342  * reconfiguration such as a failover event or virtual machine
1343  * migration.
1344  */
1345 void __netdev_notify_peers(struct net_device *dev)
1346 {
1347         ASSERT_RTNL();
1348         call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
1349         call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
1350 }
1351 EXPORT_SYMBOL(__netdev_notify_peers);
1352
1353 /**
1354  * netdev_notify_peers - notify network peers about existence of @dev
1355  * @dev: network device
1356  *
1357  * Generate traffic such that interested network peers are aware of
1358  * @dev, such as by generating a gratuitous ARP. This may be used when
1359  * a device wants to inform the rest of the network about some sort of
1360  * reconfiguration such as a failover event or virtual machine
1361  * migration.
1362  */
1363 void netdev_notify_peers(struct net_device *dev)
1364 {
1365         rtnl_lock();
1366         __netdev_notify_peers(dev);
1367         rtnl_unlock();
1368 }
1369 EXPORT_SYMBOL(netdev_notify_peers);
1370
1371 static int napi_threaded_poll(void *data);
1372
1373 static int napi_kthread_create(struct napi_struct *n)
1374 {
1375         int err = 0;
1376
1377         /* Create and wake up the kthread once to put it in
1378          * TASK_INTERRUPTIBLE mode to avoid the blocked task
1379          * warning and work with loadavg.
1380          */
1381         n->thread = kthread_run(napi_threaded_poll, n, "napi/%s-%d",
1382                                 n->dev->name, n->napi_id);
1383         if (IS_ERR(n->thread)) {
1384                 err = PTR_ERR(n->thread);
1385                 pr_err("kthread_run failed with err %d\n", err);
1386                 n->thread = NULL;
1387         }
1388
1389         return err;
1390 }
1391
1392 static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1393 {
1394         const struct net_device_ops *ops = dev->netdev_ops;
1395         int ret;
1396
1397         ASSERT_RTNL();
1398         dev_addr_check(dev);
1399
1400         if (!netif_device_present(dev)) {
1401                 /* may be detached because parent is runtime-suspended */
1402                 if (dev->dev.parent)
1403                         pm_runtime_resume(dev->dev.parent);
1404                 if (!netif_device_present(dev))
1405                         return -ENODEV;
1406         }
1407
1408         /* Block netpoll from trying to do any rx path servicing.
1409          * If we don't do this there is a chance ndo_poll_controller
1410          * or ndo_poll may be running while we open the device
1411          */
1412         netpoll_poll_disable(dev);
1413
1414         ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
1415         ret = notifier_to_errno(ret);
1416         if (ret)
1417                 return ret;
1418
1419         set_bit(__LINK_STATE_START, &dev->state);
1420
1421         if (ops->ndo_validate_addr)
1422                 ret = ops->ndo_validate_addr(dev);
1423
1424         if (!ret && ops->ndo_open)
1425                 ret = ops->ndo_open(dev);
1426
1427         netpoll_poll_enable(dev);
1428
1429         if (ret)
1430                 clear_bit(__LINK_STATE_START, &dev->state);
1431         else {
1432                 dev->flags |= IFF_UP;
1433                 dev_set_rx_mode(dev);
1434                 dev_activate(dev);
1435                 add_device_randomness(dev->dev_addr, dev->addr_len);
1436         }
1437
1438         return ret;
1439 }
1440
1441 /**
1442  *      dev_open        - prepare an interface for use.
1443  *      @dev: device to open
1444  *      @extack: netlink extended ack
1445  *
1446  *      Takes a device from down to up state. The device's private open
1447  *      function is invoked and then the multicast lists are loaded. Finally
1448  *      the device is moved into the up state and a %NETDEV_UP message is
1449  *      sent to the netdev notifier chain.
1450  *
1451  *      Calling this function on an active interface is a nop. On a failure
1452  *      a negative errno code is returned.
1453  */
1454 int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
1455 {
1456         int ret;
1457
1458         if (dev->flags & IFF_UP)
1459                 return 0;
1460
1461         ret = __dev_open(dev, extack);
1462         if (ret < 0)
1463                 return ret;
1464
1465         rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1466         call_netdevice_notifiers(NETDEV_UP, dev);
1467
1468         return ret;
1469 }
1470 EXPORT_SYMBOL(dev_open);
1471
1472 static void __dev_close_many(struct list_head *head)
1473 {
1474         struct net_device *dev;
1475
1476         ASSERT_RTNL();
1477         might_sleep();
1478
1479         list_for_each_entry(dev, head, close_list) {
1480                 /* Temporarily disable netpoll until the interface is down */
1481                 netpoll_poll_disable(dev);
1482
1483                 call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
1484
1485                 clear_bit(__LINK_STATE_START, &dev->state);
1486
1487                 /* Synchronize to scheduled poll. We cannot touch poll list, it
1488                  * can be even on different cpu. So just clear netif_running().
1489                  *
1490                  * dev->stop() will invoke napi_disable() on all of it's
1491                  * napi_struct instances on this device.
1492                  */
1493                 smp_mb__after_atomic(); /* Commit netif_running(). */
1494         }
1495
1496         dev_deactivate_many(head);
1497
1498         list_for_each_entry(dev, head, close_list) {
1499                 const struct net_device_ops *ops = dev->netdev_ops;
1500
1501                 /*
1502                  *      Call the device specific close. This cannot fail.
1503                  *      Only if device is UP
1504                  *
1505                  *      We allow it to be called even after a DETACH hot-plug
1506                  *      event.
1507                  */
1508                 if (ops->ndo_stop)
1509                         ops->ndo_stop(dev);
1510
1511                 dev->flags &= ~IFF_UP;
1512                 netpoll_poll_enable(dev);
1513         }
1514 }
1515
1516 static void __dev_close(struct net_device *dev)
1517 {
1518         LIST_HEAD(single);
1519
1520         list_add(&dev->close_list, &single);
1521         __dev_close_many(&single);
1522         list_del(&single);
1523 }
1524
1525 void dev_close_many(struct list_head *head, bool unlink)
1526 {
1527         struct net_device *dev, *tmp;
1528
1529         /* Remove the devices that don't need to be closed */
1530         list_for_each_entry_safe(dev, tmp, head, close_list)
1531                 if (!(dev->flags & IFF_UP))
1532                         list_del_init(&dev->close_list);
1533
1534         __dev_close_many(head);
1535
1536         list_for_each_entry_safe(dev, tmp, head, close_list) {
1537                 rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
1538                 call_netdevice_notifiers(NETDEV_DOWN, dev);
1539                 if (unlink)
1540                         list_del_init(&dev->close_list);
1541         }
1542 }
1543 EXPORT_SYMBOL(dev_close_many);
1544
1545 /**
1546  *      dev_close - shutdown an interface.
1547  *      @dev: device to shutdown
1548  *
1549  *      This function moves an active device into down state. A
1550  *      %NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
1551  *      is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
1552  *      chain.
1553  */
1554 void dev_close(struct net_device *dev)
1555 {
1556         if (dev->flags & IFF_UP) {
1557                 LIST_HEAD(single);
1558
1559                 list_add(&dev->close_list, &single);
1560                 dev_close_many(&single, true);
1561                 list_del(&single);
1562         }
1563 }
1564 EXPORT_SYMBOL(dev_close);
1565
1566
1567 /**
1568  *      dev_disable_lro - disable Large Receive Offload on a device
1569  *      @dev: device
1570  *
1571  *      Disable Large Receive Offload (LRO) on a net device.  Must be
1572  *      called under RTNL.  This is needed if received packets may be
1573  *      forwarded to another interface.
1574  */
1575 void dev_disable_lro(struct net_device *dev)
1576 {
1577         struct net_device *lower_dev;
1578         struct list_head *iter;
1579
1580         dev->wanted_features &= ~NETIF_F_LRO;
1581         netdev_update_features(dev);
1582
1583         if (unlikely(dev->features & NETIF_F_LRO))
1584                 netdev_WARN(dev, "failed to disable LRO!\n");
1585
1586         netdev_for_each_lower_dev(dev, lower_dev, iter)
1587                 dev_disable_lro(lower_dev);
1588 }
1589 EXPORT_SYMBOL(dev_disable_lro);
1590
1591 /**
1592  *      dev_disable_gro_hw - disable HW Generic Receive Offload on a device
1593  *      @dev: device
1594  *
1595  *      Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
1596  *      called under RTNL.  This is needed if Generic XDP is installed on
1597  *      the device.
1598  */
1599 static void dev_disable_gro_hw(struct net_device *dev)
1600 {
1601         dev->wanted_features &= ~NETIF_F_GRO_HW;
1602         netdev_update_features(dev);
1603
1604         if (unlikely(dev->features & NETIF_F_GRO_HW))
1605                 netdev_WARN(dev, "failed to disable GRO_HW!\n");
1606 }
1607
1608 const char *netdev_cmd_to_name(enum netdev_cmd cmd)
1609 {
1610 #define N(val)                                          \
1611         case NETDEV_##val:                              \
1612                 return "NETDEV_" __stringify(val);
1613         switch (cmd) {
1614         N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
1615         N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
1616         N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
1617         N(POST_INIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN) N(CHANGEUPPER)
1618         N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
1619         N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
1620         N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
1621         N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
1622         N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
1623         N(PRE_CHANGEADDR) N(OFFLOAD_XSTATS_ENABLE) N(OFFLOAD_XSTATS_DISABLE)
1624         N(OFFLOAD_XSTATS_REPORT_USED) N(OFFLOAD_XSTATS_REPORT_DELTA)
1625         }
1626 #undef N
1627         return "UNKNOWN_NETDEV_EVENT";
1628 }
1629 EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
1630
1631 static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
1632                                    struct net_device *dev)
1633 {
1634         struct netdev_notifier_info info = {
1635                 .dev = dev,
1636         };
1637
1638         return nb->notifier_call(nb, val, &info);
1639 }
1640
1641 static int call_netdevice_register_notifiers(struct notifier_block *nb,
1642                                              struct net_device *dev)
1643 {
1644         int err;
1645
1646         err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
1647         err = notifier_to_errno(err);
1648         if (err)
1649                 return err;
1650
1651         if (!(dev->flags & IFF_UP))
1652                 return 0;
1653
1654         call_netdevice_notifier(nb, NETDEV_UP, dev);
1655         return 0;
1656 }
1657
1658 static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
1659                                                 struct net_device *dev)
1660 {
1661         if (dev->flags & IFF_UP) {
1662                 call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
1663                                         dev);
1664                 call_netdevice_notifier(nb, NETDEV_DOWN, dev);
1665         }
1666         call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
1667 }
1668
1669 static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
1670                                                  struct net *net)
1671 {
1672         struct net_device *dev;
1673         int err;
1674
1675         for_each_netdev(net, dev) {
1676                 err = call_netdevice_register_notifiers(nb, dev);
1677                 if (err)
1678                         goto rollback;
1679         }
1680         return 0;
1681
1682 rollback:
1683         for_each_netdev_continue_reverse(net, dev)
1684                 call_netdevice_unregister_notifiers(nb, dev);
1685         return err;
1686 }
1687
1688 static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
1689                                                     struct net *net)
1690 {
1691         struct net_device *dev;
1692
1693         for_each_netdev(net, dev)
1694                 call_netdevice_unregister_notifiers(nb, dev);
1695 }
1696
1697 static int dev_boot_phase = 1;
1698
1699 /**
1700  * register_netdevice_notifier - register a network notifier block
1701  * @nb: notifier
1702  *
1703  * Register a notifier to be called when network device events occur.
1704  * The notifier passed is linked into the kernel structures and must
1705  * not be reused until it has been unregistered. A negative errno code
1706  * is returned on a failure.
1707  *
1708  * When registered all registration and up events are replayed
1709  * to the new notifier to allow device to have a race free
1710  * view of the network device list.
1711  */
1712
1713 int register_netdevice_notifier(struct notifier_block *nb)
1714 {
1715         struct net *net;
1716         int err;
1717
1718         /* Close race with setup_net() and cleanup_net() */
1719         down_write(&pernet_ops_rwsem);
1720         rtnl_lock();
1721         err = raw_notifier_chain_register(&netdev_chain, nb);
1722         if (err)
1723                 goto unlock;
1724         if (dev_boot_phase)
1725                 goto unlock;
1726         for_each_net(net) {
1727                 err = call_netdevice_register_net_notifiers(nb, net);
1728                 if (err)
1729                         goto rollback;
1730         }
1731
1732 unlock:
1733         rtnl_unlock();
1734         up_write(&pernet_ops_rwsem);
1735         return err;
1736
1737 rollback:
1738         for_each_net_continue_reverse(net)
1739                 call_netdevice_unregister_net_notifiers(nb, net);
1740
1741         raw_notifier_chain_unregister(&netdev_chain, nb);
1742         goto unlock;
1743 }
1744 EXPORT_SYMBOL(register_netdevice_notifier);
1745
1746 /**
1747  * unregister_netdevice_notifier - unregister a network notifier block
1748  * @nb: notifier
1749  *
1750  * Unregister a notifier previously registered by
1751  * register_netdevice_notifier(). The notifier is unlinked into the
1752  * kernel structures and may then be reused. A negative errno code
1753  * is returned on a failure.
1754  *
1755  * After unregistering unregister and down device events are synthesized
1756  * for all devices on the device list to the removed notifier to remove
1757  * the need for special case cleanup code.
1758  */
1759
1760 int unregister_netdevice_notifier(struct notifier_block *nb)
1761 {
1762         struct net *net;
1763         int err;
1764
1765         /* Close race with setup_net() and cleanup_net() */
1766         down_write(&pernet_ops_rwsem);
1767         rtnl_lock();
1768         err = raw_notifier_chain_unregister(&netdev_chain, nb);
1769         if (err)
1770                 goto unlock;
1771
1772         for_each_net(net)
1773                 call_netdevice_unregister_net_notifiers(nb, net);
1774
1775 unlock:
1776         rtnl_unlock();
1777         up_write(&pernet_ops_rwsem);
1778         return err;
1779 }
1780 EXPORT_SYMBOL(unregister_netdevice_notifier);
1781
1782 static int __register_netdevice_notifier_net(struct net *net,
1783                                              struct notifier_block *nb,
1784                                              bool ignore_call_fail)
1785 {
1786         int err;
1787
1788         err = raw_notifier_chain_register(&net->netdev_chain, nb);
1789         if (err)
1790                 return err;
1791         if (dev_boot_phase)
1792                 return 0;
1793
1794         err = call_netdevice_register_net_notifiers(nb, net);
1795         if (err && !ignore_call_fail)
1796                 goto chain_unregister;
1797
1798         return 0;
1799
1800 chain_unregister:
1801         raw_notifier_chain_unregister(&net->netdev_chain, nb);
1802         return err;
1803 }
1804
1805 static int __unregister_netdevice_notifier_net(struct net *net,
1806                                                struct notifier_block *nb)
1807 {
1808         int err;
1809
1810         err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
1811         if (err)
1812                 return err;
1813
1814         call_netdevice_unregister_net_notifiers(nb, net);
1815         return 0;
1816 }
1817
1818 /**
1819  * register_netdevice_notifier_net - register a per-netns network notifier block
1820  * @net: network namespace
1821  * @nb: notifier
1822  *
1823  * Register a notifier to be called when network device events occur.
1824  * The notifier passed is linked into the kernel structures and must
1825  * not be reused until it has been unregistered. A negative errno code
1826  * is returned on a failure.
1827  *
1828  * When registered all registration and up events are replayed
1829  * to the new notifier to allow device to have a race free
1830  * view of the network device list.
1831  */
1832
1833 int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
1834 {
1835         int err;
1836
1837         rtnl_lock();
1838         err = __register_netdevice_notifier_net(net, nb, false);
1839         rtnl_unlock();
1840         return err;
1841 }
1842 EXPORT_SYMBOL(register_netdevice_notifier_net);
1843
1844 /**
1845  * unregister_netdevice_notifier_net - unregister a per-netns
1846  *                                     network notifier block
1847  * @net: network namespace
1848  * @nb: notifier
1849  *
1850  * Unregister a notifier previously registered by
1851  * register_netdevice_notifier(). The notifier is unlinked into the
1852  * kernel structures and may then be reused. A negative errno code
1853  * is returned on a failure.
1854  *
1855  * After unregistering unregister and down device events are synthesized
1856  * for all devices on the device list to the removed notifier to remove
1857  * the need for special case cleanup code.
1858  */
1859
1860 int unregister_netdevice_notifier_net(struct net *net,
1861                                       struct notifier_block *nb)
1862 {
1863         int err;
1864
1865         rtnl_lock();
1866         err = __unregister_netdevice_notifier_net(net, nb);
1867         rtnl_unlock();
1868         return err;
1869 }
1870 EXPORT_SYMBOL(unregister_netdevice_notifier_net);
1871
1872 int register_netdevice_notifier_dev_net(struct net_device *dev,
1873                                         struct notifier_block *nb,
1874                                         struct netdev_net_notifier *nn)
1875 {
1876         int err;
1877
1878         rtnl_lock();
1879         err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
1880         if (!err) {
1881                 nn->nb = nb;
1882                 list_add(&nn->list, &dev->net_notifier_list);
1883         }
1884         rtnl_unlock();
1885         return err;
1886 }
1887 EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
1888
1889 int unregister_netdevice_notifier_dev_net(struct net_device *dev,
1890                                           struct notifier_block *nb,
1891                                           struct netdev_net_notifier *nn)
1892 {
1893         int err;
1894
1895         rtnl_lock();
1896         list_del(&nn->list);
1897         err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
1898         rtnl_unlock();
1899         return err;
1900 }
1901 EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
1902
1903 static void move_netdevice_notifiers_dev_net(struct net_device *dev,
1904                                              struct net *net)
1905 {
1906         struct netdev_net_notifier *nn;
1907
1908         list_for_each_entry(nn, &dev->net_notifier_list, list) {
1909                 __unregister_netdevice_notifier_net(dev_net(dev), nn->nb);
1910                 __register_netdevice_notifier_net(net, nn->nb, true);
1911         }
1912 }
1913
1914 /**
1915  *      call_netdevice_notifiers_info - call all network notifier blocks
1916  *      @val: value passed unmodified to notifier function
1917  *      @info: notifier information data
1918  *
1919  *      Call all network notifier blocks.  Parameters and return value
1920  *      are as for raw_notifier_call_chain().
1921  */
1922
1923 static int call_netdevice_notifiers_info(unsigned long val,
1924                                          struct netdev_notifier_info *info)
1925 {
1926         struct net *net = dev_net(info->dev);
1927         int ret;
1928
1929         ASSERT_RTNL();
1930
1931         /* Run per-netns notifier block chain first, then run the global one.
1932          * Hopefully, one day, the global one is going to be removed after
1933          * all notifier block registrators get converted to be per-netns.
1934          */
1935         ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
1936         if (ret & NOTIFY_STOP_MASK)
1937                 return ret;
1938         return raw_notifier_call_chain(&netdev_chain, val, info);
1939 }
1940
1941 /**
1942  *      call_netdevice_notifiers_info_robust - call per-netns notifier blocks
1943  *                                             for and rollback on error
1944  *      @val_up: value passed unmodified to notifier function
1945  *      @val_down: value passed unmodified to the notifier function when
1946  *                 recovering from an error on @val_up
1947  *      @info: notifier information data
1948  *
1949  *      Call all per-netns network notifier blocks, but not notifier blocks on
1950  *      the global notifier chain. Parameters and return value are as for
1951  *      raw_notifier_call_chain_robust().
1952  */
1953
1954 static int
1955 call_netdevice_notifiers_info_robust(unsigned long val_up,
1956                                      unsigned long val_down,
1957                                      struct netdev_notifier_info *info)
1958 {
1959         struct net *net = dev_net(info->dev);
1960
1961         ASSERT_RTNL();
1962
1963         return raw_notifier_call_chain_robust(&net->netdev_chain,
1964                                               val_up, val_down, info);
1965 }
1966
1967 static int call_netdevice_notifiers_extack(unsigned long val,
1968                                            struct net_device *dev,
1969                                            struct netlink_ext_ack *extack)
1970 {
1971         struct netdev_notifier_info info = {
1972                 .dev = dev,
1973                 .extack = extack,
1974         };
1975
1976         return call_netdevice_notifiers_info(val, &info);
1977 }
1978
1979 /**
1980  *      call_netdevice_notifiers - call all network notifier blocks
1981  *      @val: value passed unmodified to notifier function
1982  *      @dev: net_device pointer passed unmodified to notifier function
1983  *
1984  *      Call all network notifier blocks.  Parameters and return value
1985  *      are as for raw_notifier_call_chain().
1986  */
1987
1988 int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
1989 {
1990         return call_netdevice_notifiers_extack(val, dev, NULL);
1991 }
1992 EXPORT_SYMBOL(call_netdevice_notifiers);
1993
1994 /**
1995  *      call_netdevice_notifiers_mtu - call all network notifier blocks
1996  *      @val: value passed unmodified to notifier function
1997  *      @dev: net_device pointer passed unmodified to notifier function
1998  *      @arg: additional u32 argument passed to the notifier function
1999  *
2000  *      Call all network notifier blocks.  Parameters and return value
2001  *      are as for raw_notifier_call_chain().
2002  */
2003 static int call_netdevice_notifiers_mtu(unsigned long val,
2004                                         struct net_device *dev, u32 arg)
2005 {
2006         struct netdev_notifier_info_ext info = {
2007                 .info.dev = dev,
2008                 .ext.mtu = arg,
2009         };
2010
2011         BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
2012
2013         return call_netdevice_notifiers_info(val, &info.info);
2014 }
2015
2016 #ifdef CONFIG_NET_INGRESS
2017 static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
2018
2019 void net_inc_ingress_queue(void)
2020 {
2021         static_branch_inc(&ingress_needed_key);
2022 }
2023 EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
2024
2025 void net_dec_ingress_queue(void)
2026 {
2027         static_branch_dec(&ingress_needed_key);
2028 }
2029 EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
2030 #endif
2031
2032 #ifdef CONFIG_NET_EGRESS
2033 static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
2034
2035 void net_inc_egress_queue(void)
2036 {
2037         static_branch_inc(&egress_needed_key);
2038 }
2039 EXPORT_SYMBOL_GPL(net_inc_egress_queue);
2040
2041 void net_dec_egress_queue(void)
2042 {
2043         static_branch_dec(&egress_needed_key);
2044 }
2045 EXPORT_SYMBOL_GPL(net_dec_egress_queue);
2046 #endif
2047
2048 DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
2049 EXPORT_SYMBOL(netstamp_needed_key);
2050 #ifdef CONFIG_JUMP_LABEL
2051 static atomic_t netstamp_needed_deferred;
2052 static atomic_t netstamp_wanted;
2053 static void netstamp_clear(struct work_struct *work)
2054 {
2055         int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
2056         int wanted;
2057
2058         wanted = atomic_add_return(deferred, &netstamp_wanted);
2059         if (wanted > 0)
2060                 static_branch_enable(&netstamp_needed_key);
2061         else
2062                 static_branch_disable(&netstamp_needed_key);
2063 }
2064 static DECLARE_WORK(netstamp_work, netstamp_clear);
2065 #endif
2066
2067 void net_enable_timestamp(void)
2068 {
2069 #ifdef CONFIG_JUMP_LABEL
2070         int wanted;
2071
2072         while (1) {
2073                 wanted = atomic_read(&netstamp_wanted);
2074                 if (wanted <= 0)
2075                         break;
2076                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
2077                         return;
2078         }
2079         atomic_inc(&netstamp_needed_deferred);
2080         schedule_work(&netstamp_work);
2081 #else
2082         static_branch_inc(&netstamp_needed_key);
2083 #endif
2084 }
2085 EXPORT_SYMBOL(net_enable_timestamp);
2086
2087 void net_disable_timestamp(void)
2088 {
2089 #ifdef CONFIG_JUMP_LABEL
2090         int wanted;
2091
2092         while (1) {
2093                 wanted = atomic_read(&netstamp_wanted);
2094                 if (wanted <= 1)
2095                         break;
2096                 if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
2097                         return;
2098         }
2099         atomic_dec(&netstamp_needed_deferred);
2100         schedule_work(&netstamp_work);
2101 #else
2102         static_branch_dec(&netstamp_needed_key);
2103 #endif
2104 }
2105 EXPORT_SYMBOL(net_disable_timestamp);
2106
2107 static inline void net_timestamp_set(struct sk_buff *skb)
2108 {
2109         skb->tstamp = 0;
2110         skb->mono_delivery_time = 0;
2111         if (static_branch_unlikely(&netstamp_needed_key))
2112                 skb->tstamp = ktime_get_real();
2113 }
2114
2115 #define net_timestamp_check(COND, SKB)                          \
2116         if (static_branch_unlikely(&netstamp_needed_key)) {     \
2117                 if ((COND) && !(SKB)->tstamp)                   \
2118                         (SKB)->tstamp = ktime_get_real();       \
2119         }                                                       \
2120
2121 bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
2122 {
2123         return __is_skb_forwardable(dev, skb, true);
2124 }
2125 EXPORT_SYMBOL_GPL(is_skb_forwardable);
2126
2127 static int __dev_forward_skb2(struct net_device *dev, struct sk_buff *skb,
2128                               bool check_mtu)
2129 {
2130         int ret = ____dev_forward_skb(dev, skb, check_mtu);
2131
2132         if (likely(!ret)) {
2133                 skb->protocol = eth_type_trans(skb, dev);
2134                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
2135         }
2136
2137         return ret;
2138 }
2139
2140 int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2141 {
2142         return __dev_forward_skb2(dev, skb, true);
2143 }
2144 EXPORT_SYMBOL_GPL(__dev_forward_skb);
2145
2146 /**
2147  * dev_forward_skb - loopback an skb to another netif
2148  *
2149  * @dev: destination network device
2150  * @skb: buffer to forward
2151  *
2152  * return values:
2153  *      NET_RX_SUCCESS  (no congestion)
2154  *      NET_RX_DROP     (packet was dropped, but freed)
2155  *
2156  * dev_forward_skb can be used for injecting an skb from the
2157  * start_xmit function of one device into the receive queue
2158  * of another device.
2159  *
2160  * The receiving device may be in another namespace, so
2161  * we have to clear all information in the skb that could
2162  * impact namespace isolation.
2163  */
2164 int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
2165 {
2166         return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
2167 }
2168 EXPORT_SYMBOL_GPL(dev_forward_skb);
2169
2170 int dev_forward_skb_nomtu(struct net_device *dev, struct sk_buff *skb)
2171 {
2172         return __dev_forward_skb2(dev, skb, false) ?: netif_rx_internal(skb);
2173 }
2174
2175 static inline int deliver_skb(struct sk_buff *skb,
2176                               struct packet_type *pt_prev,
2177                               struct net_device *orig_dev)
2178 {
2179         if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
2180                 return -ENOMEM;
2181         refcount_inc(&skb->users);
2182         return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
2183 }
2184
2185 static inline void deliver_ptype_list_skb(struct sk_buff *skb,
2186                                           struct packet_type **pt,
2187                                           struct net_device *orig_dev,
2188                                           __be16 type,
2189                                           struct list_head *ptype_list)
2190 {
2191         struct packet_type *ptype, *pt_prev = *pt;
2192
2193         list_for_each_entry_rcu(ptype, ptype_list, list) {
2194                 if (ptype->type != type)
2195                         continue;
2196                 if (pt_prev)
2197                         deliver_skb(skb, pt_prev, orig_dev);
2198                 pt_prev = ptype;
2199         }
2200         *pt = pt_prev;
2201 }
2202
2203 static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
2204 {
2205         if (!ptype->af_packet_priv || !skb->sk)
2206                 return false;
2207
2208         if (ptype->id_match)
2209                 return ptype->id_match(ptype, skb->sk);
2210         else if ((struct sock *)ptype->af_packet_priv == skb->sk)
2211                 return true;
2212
2213         return false;
2214 }
2215
2216 /**
2217  * dev_nit_active - return true if any network interface taps are in use
2218  *
2219  * @dev: network device to check for the presence of taps
2220  */
2221 bool dev_nit_active(struct net_device *dev)
2222 {
2223         return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
2224 }
2225 EXPORT_SYMBOL_GPL(dev_nit_active);
2226
2227 /*
2228  *      Support routine. Sends outgoing frames to any network
2229  *      taps currently in use.
2230  */
2231
2232 void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
2233 {
2234         struct packet_type *ptype;
2235         struct sk_buff *skb2 = NULL;
2236         struct packet_type *pt_prev = NULL;
2237         struct list_head *ptype_list = &ptype_all;
2238
2239         rcu_read_lock();
2240 again:
2241         list_for_each_entry_rcu(ptype, ptype_list, list) {
2242                 if (ptype->ignore_outgoing)
2243                         continue;
2244
2245                 /* Never send packets back to the socket
2246                  * they originated from - MvS (miquels@drinkel.ow.org)
2247                  */
2248                 if (skb_loop_sk(ptype, skb))
2249                         continue;
2250
2251                 if (pt_prev) {
2252                         deliver_skb(skb2, pt_prev, skb->dev);
2253                         pt_prev = ptype;
2254                         continue;
2255                 }
2256
2257                 /* need to clone skb, done only once */
2258                 skb2 = skb_clone(skb, GFP_ATOMIC);
2259                 if (!skb2)
2260                         goto out_unlock;
2261
2262                 net_timestamp_set(skb2);
2263
2264                 /* skb->nh should be correctly
2265                  * set by sender, so that the second statement is
2266                  * just protection against buggy protocols.
2267                  */
2268                 skb_reset_mac_header(skb2);
2269
2270                 if (skb_network_header(skb2) < skb2->data ||
2271                     skb_network_header(skb2) > skb_tail_pointer(skb2)) {
2272                         net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
2273                                              ntohs(skb2->protocol),
2274                                              dev->name);
2275                         skb_reset_network_header(skb2);
2276                 }
2277
2278                 skb2->transport_header = skb2->network_header;
2279                 skb2->pkt_type = PACKET_OUTGOING;
2280                 pt_prev = ptype;
2281         }
2282
2283         if (ptype_list == &ptype_all) {
2284                 ptype_list = &dev->ptype_all;
2285                 goto again;
2286         }
2287 out_unlock:
2288         if (pt_prev) {
2289                 if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
2290                         pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
2291                 else
2292                         kfree_skb(skb2);
2293         }
2294         rcu_read_unlock();
2295 }
2296 EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
2297
2298 /**
2299  * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
2300  * @dev: Network device
2301  * @txq: number of queues available
2302  *
2303  * If real_num_tx_queues is changed the tc mappings may no longer be
2304  * valid. To resolve this verify the tc mapping remains valid and if
2305  * not NULL the mapping. With no priorities mapping to this
2306  * offset/count pair it will no longer be used. In the worst case TC0
2307  * is invalid nothing can be done so disable priority mappings. If is
2308  * expected that drivers will fix this mapping if they can before
2309  * calling netif_set_real_num_tx_queues.
2310  */
2311 static void netif_setup_tc(struct net_device *dev, unsigned int txq)
2312 {
2313         int i;
2314         struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2315
2316         /* If TC0 is invalidated disable TC mapping */
2317         if (tc->offset + tc->count > txq) {
2318                 netdev_warn(dev, "Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
2319                 dev->num_tc = 0;
2320                 return;
2321         }
2322
2323         /* Invalidated prio to tc mappings set to TC0 */
2324         for (i = 1; i < TC_BITMASK + 1; i++) {
2325                 int q = netdev_get_prio_tc_map(dev, i);
2326
2327                 tc = &dev->tc_to_txq[q];
2328                 if (tc->offset + tc->count > txq) {
2329                         netdev_warn(dev, "Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
2330                                     i, q);
2331                         netdev_set_prio_tc_map(dev, i, 0);
2332                 }
2333         }
2334 }
2335
2336 int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
2337 {
2338         if (dev->num_tc) {
2339                 struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
2340                 int i;
2341
2342                 /* walk through the TCs and see if it falls into any of them */
2343                 for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
2344                         if ((txq - tc->offset) < tc->count)
2345                                 return i;
2346                 }
2347
2348                 /* didn't find it, just return -1 to indicate no match */
2349                 return -1;
2350         }
2351
2352         return 0;
2353 }
2354 EXPORT_SYMBOL(netdev_txq_to_tc);
2355
2356 #ifdef CONFIG_XPS
2357 static struct static_key xps_needed __read_mostly;
2358 static struct static_key xps_rxqs_needed __read_mostly;
2359 static DEFINE_MUTEX(xps_map_mutex);
2360 #define xmap_dereference(P)             \
2361         rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
2362
2363 static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
2364                              struct xps_dev_maps *old_maps, int tci, u16 index)
2365 {
2366         struct xps_map *map = NULL;
2367         int pos;
2368
2369         if (dev_maps)
2370                 map = xmap_dereference(dev_maps->attr_map[tci]);
2371         if (!map)
2372                 return false;
2373
2374         for (pos = map->len; pos--;) {
2375                 if (map->queues[pos] != index)
2376                         continue;
2377
2378                 if (map->len > 1) {
2379                         map->queues[pos] = map->queues[--map->len];
2380                         break;
2381                 }
2382
2383                 if (old_maps)
2384                         RCU_INIT_POINTER(old_maps->attr_map[tci], NULL);
2385                 RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2386                 kfree_rcu(map, rcu);
2387                 return false;
2388         }
2389
2390         return true;
2391 }
2392
2393 static bool remove_xps_queue_cpu(struct net_device *dev,
2394                                  struct xps_dev_maps *dev_maps,
2395                                  int cpu, u16 offset, u16 count)
2396 {
2397         int num_tc = dev_maps->num_tc;
2398         bool active = false;
2399         int tci;
2400
2401         for (tci = cpu * num_tc; num_tc--; tci++) {
2402                 int i, j;
2403
2404                 for (i = count, j = offset; i--; j++) {
2405                         if (!remove_xps_queue(dev_maps, NULL, tci, j))
2406                                 break;
2407                 }
2408
2409                 active |= i < 0;
2410         }
2411
2412         return active;
2413 }
2414
2415 static void reset_xps_maps(struct net_device *dev,
2416                            struct xps_dev_maps *dev_maps,
2417                            enum xps_map_type type)
2418 {
2419         static_key_slow_dec_cpuslocked(&xps_needed);
2420         if (type == XPS_RXQS)
2421                 static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
2422
2423         RCU_INIT_POINTER(dev->xps_maps[type], NULL);
2424
2425         kfree_rcu(dev_maps, rcu);
2426 }
2427
2428 static void clean_xps_maps(struct net_device *dev, enum xps_map_type type,
2429                            u16 offset, u16 count)
2430 {
2431         struct xps_dev_maps *dev_maps;
2432         bool active = false;
2433         int i, j;
2434
2435         dev_maps = xmap_dereference(dev->xps_maps[type]);
2436         if (!dev_maps)
2437                 return;
2438
2439         for (j = 0; j < dev_maps->nr_ids; j++)
2440                 active |= remove_xps_queue_cpu(dev, dev_maps, j, offset, count);
2441         if (!active)
2442                 reset_xps_maps(dev, dev_maps, type);
2443
2444         if (type == XPS_CPUS) {
2445                 for (i = offset + (count - 1); count--; i--)
2446                         netdev_queue_numa_node_write(
2447                                 netdev_get_tx_queue(dev, i), NUMA_NO_NODE);
2448         }
2449 }
2450
2451 static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
2452                                    u16 count)
2453 {
2454         if (!static_key_false(&xps_needed))
2455                 return;
2456
2457         cpus_read_lock();
2458         mutex_lock(&xps_map_mutex);
2459
2460         if (static_key_false(&xps_rxqs_needed))
2461                 clean_xps_maps(dev, XPS_RXQS, offset, count);
2462
2463         clean_xps_maps(dev, XPS_CPUS, offset, count);
2464
2465         mutex_unlock(&xps_map_mutex);
2466         cpus_read_unlock();
2467 }
2468
2469 static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
2470 {
2471         netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
2472 }
2473
2474 static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
2475                                       u16 index, bool is_rxqs_map)
2476 {
2477         struct xps_map *new_map;
2478         int alloc_len = XPS_MIN_MAP_ALLOC;
2479         int i, pos;
2480
2481         for (pos = 0; map && pos < map->len; pos++) {
2482                 if (map->queues[pos] != index)
2483                         continue;
2484                 return map;
2485         }
2486
2487         /* Need to add tx-queue to this CPU's/rx-queue's existing map */
2488         if (map) {
2489                 if (pos < map->alloc_len)
2490                         return map;
2491
2492                 alloc_len = map->alloc_len * 2;
2493         }
2494
2495         /* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
2496          *  map
2497          */
2498         if (is_rxqs_map)
2499                 new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
2500         else
2501                 new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
2502                                        cpu_to_node(attr_index));
2503         if (!new_map)
2504                 return NULL;
2505
2506         for (i = 0; i < pos; i++)
2507                 new_map->queues[i] = map->queues[i];
2508         new_map->alloc_len = alloc_len;
2509         new_map->len = pos;
2510
2511         return new_map;
2512 }
2513
2514 /* Copy xps maps at a given index */
2515 static void xps_copy_dev_maps(struct xps_dev_maps *dev_maps,
2516                               struct xps_dev_maps *new_dev_maps, int index,
2517                               int tc, bool skip_tc)
2518 {
2519         int i, tci = index * dev_maps->num_tc;
2520         struct xps_map *map;
2521
2522         /* copy maps belonging to foreign traffic classes */
2523         for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2524                 if (i == tc && skip_tc)
2525                         continue;
2526
2527                 /* fill in the new device map from the old device map */
2528                 map = xmap_dereference(dev_maps->attr_map[tci]);
2529                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2530         }
2531 }
2532
2533 /* Must be called under cpus_read_lock */
2534 int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
2535                           u16 index, enum xps_map_type type)
2536 {
2537         struct xps_dev_maps *dev_maps, *new_dev_maps = NULL, *old_dev_maps = NULL;
2538         const unsigned long *online_mask = NULL;
2539         bool active = false, copy = false;
2540         int i, j, tci, numa_node_id = -2;
2541         int maps_sz, num_tc = 1, tc = 0;
2542         struct xps_map *map, *new_map;
2543         unsigned int nr_ids;
2544
2545         if (dev->num_tc) {
2546                 /* Do not allow XPS on subordinate device directly */
2547                 num_tc = dev->num_tc;
2548                 if (num_tc < 0)
2549                         return -EINVAL;
2550
2551                 /* If queue belongs to subordinate dev use its map */
2552                 dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
2553
2554                 tc = netdev_txq_to_tc(dev, index);
2555                 if (tc < 0)
2556                         return -EINVAL;
2557         }
2558
2559         mutex_lock(&xps_map_mutex);
2560
2561         dev_maps = xmap_dereference(dev->xps_maps[type]);
2562         if (type == XPS_RXQS) {
2563                 maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
2564                 nr_ids = dev->num_rx_queues;
2565         } else {
2566                 maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
2567                 if (num_possible_cpus() > 1)
2568                         online_mask = cpumask_bits(cpu_online_mask);
2569                 nr_ids = nr_cpu_ids;
2570         }
2571
2572         if (maps_sz < L1_CACHE_BYTES)
2573                 maps_sz = L1_CACHE_BYTES;
2574
2575         /* The old dev_maps could be larger or smaller than the one we're
2576          * setting up now, as dev->num_tc or nr_ids could have been updated in
2577          * between. We could try to be smart, but let's be safe instead and only
2578          * copy foreign traffic classes if the two map sizes match.
2579          */
2580         if (dev_maps &&
2581             dev_maps->num_tc == num_tc && dev_maps->nr_ids == nr_ids)
2582                 copy = true;
2583
2584         /* allocate memory for queue storage */
2585         for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
2586              j < nr_ids;) {
2587                 if (!new_dev_maps) {
2588                         new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
2589                         if (!new_dev_maps) {
2590                                 mutex_unlock(&xps_map_mutex);
2591                                 return -ENOMEM;
2592                         }
2593
2594                         new_dev_maps->nr_ids = nr_ids;
2595                         new_dev_maps->num_tc = num_tc;
2596                 }
2597
2598                 tci = j * num_tc + tc;
2599                 map = copy ? xmap_dereference(dev_maps->attr_map[tci]) : NULL;
2600
2601                 map = expand_xps_map(map, j, index, type == XPS_RXQS);
2602                 if (!map)
2603                         goto error;
2604
2605                 RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
2606         }
2607
2608         if (!new_dev_maps)
2609                 goto out_no_new_maps;
2610
2611         if (!dev_maps) {
2612                 /* Increment static keys at most once per type */
2613                 static_key_slow_inc_cpuslocked(&xps_needed);
2614                 if (type == XPS_RXQS)
2615                         static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
2616         }
2617
2618         for (j = 0; j < nr_ids; j++) {
2619                 bool skip_tc = false;
2620
2621                 tci = j * num_tc + tc;
2622                 if (netif_attr_test_mask(j, mask, nr_ids) &&
2623                     netif_attr_test_online(j, online_mask, nr_ids)) {
2624                         /* add tx-queue to CPU/rx-queue maps */
2625                         int pos = 0;
2626
2627                         skip_tc = true;
2628
2629                         map = xmap_dereference(new_dev_maps->attr_map[tci]);
2630                         while ((pos < map->len) && (map->queues[pos] != index))
2631                                 pos++;
2632
2633                         if (pos == map->len)
2634                                 map->queues[map->len++] = index;
2635 #ifdef CONFIG_NUMA
2636                         if (type == XPS_CPUS) {
2637                                 if (numa_node_id == -2)
2638                                         numa_node_id = cpu_to_node(j);
2639                                 else if (numa_node_id != cpu_to_node(j))
2640                                         numa_node_id = -1;
2641                         }
2642 #endif
2643                 }
2644
2645                 if (copy)
2646                         xps_copy_dev_maps(dev_maps, new_dev_maps, j, tc,
2647                                           skip_tc);
2648         }
2649
2650         rcu_assign_pointer(dev->xps_maps[type], new_dev_maps);
2651
2652         /* Cleanup old maps */
2653         if (!dev_maps)
2654                 goto out_no_old_maps;
2655
2656         for (j = 0; j < dev_maps->nr_ids; j++) {
2657                 for (i = num_tc, tci = j * dev_maps->num_tc; i--; tci++) {
2658                         map = xmap_dereference(dev_maps->attr_map[tci]);
2659                         if (!map)
2660                                 continue;
2661
2662                         if (copy) {
2663                                 new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2664                                 if (map == new_map)
2665                                         continue;
2666                         }
2667
2668                         RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
2669                         kfree_rcu(map, rcu);
2670                 }
2671         }
2672
2673         old_dev_maps = dev_maps;
2674
2675 out_no_old_maps:
2676         dev_maps = new_dev_maps;
2677         active = true;
2678
2679 out_no_new_maps:
2680         if (type == XPS_CPUS)
2681                 /* update Tx queue numa node */
2682                 netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
2683                                              (numa_node_id >= 0) ?
2684                                              numa_node_id : NUMA_NO_NODE);
2685
2686         if (!dev_maps)
2687                 goto out_no_maps;
2688
2689         /* removes tx-queue from unused CPUs/rx-queues */
2690         for (j = 0; j < dev_maps->nr_ids; j++) {
2691                 tci = j * dev_maps->num_tc;
2692
2693                 for (i = 0; i < dev_maps->num_tc; i++, tci++) {
2694                         if (i == tc &&
2695                             netif_attr_test_mask(j, mask, dev_maps->nr_ids) &&
2696                             netif_attr_test_online(j, online_mask, dev_maps->nr_ids))
2697                                 continue;
2698
2699                         active |= remove_xps_queue(dev_maps,
2700                                                    copy ? old_dev_maps : NULL,
2701                                                    tci, index);
2702                 }
2703         }
2704
2705         if (old_dev_maps)
2706                 kfree_rcu(old_dev_maps, rcu);
2707
2708         /* free map if not active */
2709         if (!active)
2710                 reset_xps_maps(dev, dev_maps, type);
2711
2712 out_no_maps:
2713         mutex_unlock(&xps_map_mutex);
2714
2715         return 0;
2716 error:
2717         /* remove any maps that we added */
2718         for (j = 0; j < nr_ids; j++) {
2719                 for (i = num_tc, tci = j * num_tc; i--; tci++) {
2720                         new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
2721                         map = copy ?
2722                               xmap_dereference(dev_maps->attr_map[tci]) :
2723                               NULL;
2724                         if (new_map && new_map != map)
2725                                 kfree(new_map);
2726                 }
2727         }
2728
2729         mutex_unlock(&xps_map_mutex);
2730
2731         kfree(new_dev_maps);
2732         return -ENOMEM;
2733 }
2734 EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
2735
2736 int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
2737                         u16 index)
2738 {
2739         int ret;
2740
2741         cpus_read_lock();
2742         ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, XPS_CPUS);
2743         cpus_read_unlock();
2744
2745         return ret;
2746 }
2747 EXPORT_SYMBOL(netif_set_xps_queue);
2748
2749 #endif
2750 static void netdev_unbind_all_sb_channels(struct net_device *dev)
2751 {
2752         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2753
2754         /* Unbind any subordinate channels */
2755         while (txq-- != &dev->_tx[0]) {
2756                 if (txq->sb_dev)
2757                         netdev_unbind_sb_channel(dev, txq->sb_dev);
2758         }
2759 }
2760
2761 void netdev_reset_tc(struct net_device *dev)
2762 {
2763 #ifdef CONFIG_XPS
2764         netif_reset_xps_queues_gt(dev, 0);
2765 #endif
2766         netdev_unbind_all_sb_channels(dev);
2767
2768         /* Reset TC configuration of device */
2769         dev->num_tc = 0;
2770         memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
2771         memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
2772 }
2773 EXPORT_SYMBOL(netdev_reset_tc);
2774
2775 int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
2776 {
2777         if (tc >= dev->num_tc)
2778                 return -EINVAL;
2779
2780 #ifdef CONFIG_XPS
2781         netif_reset_xps_queues(dev, offset, count);
2782 #endif
2783         dev->tc_to_txq[tc].count = count;
2784         dev->tc_to_txq[tc].offset = offset;
2785         return 0;
2786 }
2787 EXPORT_SYMBOL(netdev_set_tc_queue);
2788
2789 int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
2790 {
2791         if (num_tc > TC_MAX_QUEUE)
2792                 return -EINVAL;
2793
2794 #ifdef CONFIG_XPS
2795         netif_reset_xps_queues_gt(dev, 0);
2796 #endif
2797         netdev_unbind_all_sb_channels(dev);
2798
2799         dev->num_tc = num_tc;
2800         return 0;
2801 }
2802 EXPORT_SYMBOL(netdev_set_num_tc);
2803
2804 void netdev_unbind_sb_channel(struct net_device *dev,
2805                               struct net_device *sb_dev)
2806 {
2807         struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
2808
2809 #ifdef CONFIG_XPS
2810         netif_reset_xps_queues_gt(sb_dev, 0);
2811 #endif
2812         memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
2813         memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
2814
2815         while (txq-- != &dev->_tx[0]) {
2816                 if (txq->sb_dev == sb_dev)
2817                         txq->sb_dev = NULL;
2818         }
2819 }
2820 EXPORT_SYMBOL(netdev_unbind_sb_channel);
2821
2822 int netdev_bind_sb_channel_queue(struct net_device *dev,
2823                                  struct net_device *sb_dev,
2824                                  u8 tc, u16 count, u16 offset)
2825 {
2826         /* Make certain the sb_dev and dev are already configured */
2827         if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
2828                 return -EINVAL;
2829
2830         /* We cannot hand out queues we don't have */
2831         if ((offset + count) > dev->real_num_tx_queues)
2832                 return -EINVAL;
2833
2834         /* Record the mapping */
2835         sb_dev->tc_to_txq[tc].count = count;
2836         sb_dev->tc_to_txq[tc].offset = offset;
2837
2838         /* Provide a way for Tx queue to find the tc_to_txq map or
2839          * XPS map for itself.
2840          */
2841         while (count--)
2842                 netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
2843
2844         return 0;
2845 }
2846 EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
2847
2848 int netdev_set_sb_channel(struct net_device *dev, u16 channel)
2849 {
2850         /* Do not use a multiqueue device to represent a subordinate channel */
2851         if (netif_is_multiqueue(dev))
2852                 return -ENODEV;
2853
2854         /* We allow channels 1 - 32767 to be used for subordinate channels.
2855          * Channel 0 is meant to be "native" mode and used only to represent
2856          * the main root device. We allow writing 0 to reset the device back
2857          * to normal mode after being used as a subordinate channel.
2858          */
2859         if (channel > S16_MAX)
2860                 return -EINVAL;
2861
2862         dev->num_tc = -channel;
2863
2864         return 0;
2865 }
2866 EXPORT_SYMBOL(netdev_set_sb_channel);
2867
2868 /*
2869  * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
2870  * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
2871  */
2872 int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
2873 {
2874         bool disabling;
2875         int rc;
2876
2877         disabling = txq < dev->real_num_tx_queues;
2878
2879         if (txq < 1 || txq > dev->num_tx_queues)
2880                 return -EINVAL;
2881
2882         if (dev->reg_state == NETREG_REGISTERED ||
2883             dev->reg_state == NETREG_UNREGISTERING) {
2884                 ASSERT_RTNL();
2885
2886                 rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
2887                                                   txq);
2888                 if (rc)
2889                         return rc;
2890
2891                 if (dev->num_tc)
2892                         netif_setup_tc(dev, txq);
2893
2894                 dev_qdisc_change_real_num_tx(dev, txq);
2895
2896                 dev->real_num_tx_queues = txq;
2897
2898                 if (disabling) {
2899                         synchronize_net();
2900                         qdisc_reset_all_tx_gt(dev, txq);
2901 #ifdef CONFIG_XPS
2902                         netif_reset_xps_queues_gt(dev, txq);
2903 #endif
2904                 }
2905         } else {
2906                 dev->real_num_tx_queues = txq;
2907         }
2908
2909         return 0;
2910 }
2911 EXPORT_SYMBOL(netif_set_real_num_tx_queues);
2912
2913 #ifdef CONFIG_SYSFS
2914 /**
2915  *      netif_set_real_num_rx_queues - set actual number of RX queues used
2916  *      @dev: Network device
2917  *      @rxq: Actual number of RX queues
2918  *
2919  *      This must be called either with the rtnl_lock held or before
2920  *      registration of the net device.  Returns 0 on success, or a
2921  *      negative error code.  If called before registration, it always
2922  *      succeeds.
2923  */
2924 int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
2925 {
2926         int rc;
2927
2928         if (rxq < 1 || rxq > dev->num_rx_queues)
2929                 return -EINVAL;
2930
2931         if (dev->reg_state == NETREG_REGISTERED) {
2932                 ASSERT_RTNL();
2933
2934                 rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
2935                                                   rxq);
2936                 if (rc)
2937                         return rc;
2938         }
2939
2940         dev->real_num_rx_queues = rxq;
2941         return 0;
2942 }
2943 EXPORT_SYMBOL(netif_set_real_num_rx_queues);
2944 #endif
2945
2946 /**
2947  *      netif_set_real_num_queues - set actual number of RX and TX queues used
2948  *      @dev: Network device
2949  *      @txq: Actual number of TX queues
2950  *      @rxq: Actual number of RX queues
2951  *
2952  *      Set the real number of both TX and RX queues.
2953  *      Does nothing if the number of queues is already correct.
2954  */
2955 int netif_set_real_num_queues(struct net_device *dev,
2956                               unsigned int txq, unsigned int rxq)
2957 {
2958         unsigned int old_rxq = dev->real_num_rx_queues;
2959         int err;
2960
2961         if (txq < 1 || txq > dev->num_tx_queues ||
2962             rxq < 1 || rxq > dev->num_rx_queues)
2963                 return -EINVAL;
2964
2965         /* Start from increases, so the error path only does decreases -
2966          * decreases can't fail.
2967          */
2968         if (rxq > dev->real_num_rx_queues) {
2969                 err = netif_set_real_num_rx_queues(dev, rxq);
2970                 if (err)
2971                         return err;
2972         }
2973         if (txq > dev->real_num_tx_queues) {
2974                 err = netif_set_real_num_tx_queues(dev, txq);
2975                 if (err)
2976                         goto undo_rx;
2977         }
2978         if (rxq < dev->real_num_rx_queues)
2979                 WARN_ON(netif_set_real_num_rx_queues(dev, rxq));
2980         if (txq < dev->real_num_tx_queues)
2981                 WARN_ON(netif_set_real_num_tx_queues(dev, txq));
2982
2983         return 0;
2984 undo_rx:
2985         WARN_ON(netif_set_real_num_rx_queues(dev, old_rxq));
2986         return err;
2987 }
2988 EXPORT_SYMBOL(netif_set_real_num_queues);
2989
2990 /**
2991  * netif_get_num_default_rss_queues - default number of RSS queues
2992  *
2993  * Default value is the number of physical cores if there are only 1 or 2, or
2994  * divided by 2 if there are more.
2995  */
2996 int netif_get_num_default_rss_queues(void)
2997 {
2998         cpumask_var_t cpus;
2999         int cpu, count = 0;
3000
3001         if (unlikely(is_kdump_kernel() || !zalloc_cpumask_var(&cpus, GFP_KERNEL)))
3002                 return 1;
3003
3004         cpumask_copy(cpus, cpu_online_mask);
3005         for_each_cpu(cpu, cpus) {
3006                 ++count;
3007                 cpumask_andnot(cpus, cpus, topology_sibling_cpumask(cpu));
3008         }
3009         free_cpumask_var(cpus);
3010
3011         return count > 2 ? DIV_ROUND_UP(count, 2) : count;
3012 }
3013 EXPORT_SYMBOL(netif_get_num_default_rss_queues);
3014
3015 static void __netif_reschedule(struct Qdisc *q)
3016 {
3017         struct softnet_data *sd;
3018         unsigned long flags;
3019
3020         local_irq_save(flags);
3021         sd = this_cpu_ptr(&softnet_data);
3022         q->next_sched = NULL;
3023         *sd->output_queue_tailp = q;
3024         sd->output_queue_tailp = &q->next_sched;
3025         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3026         local_irq_restore(flags);
3027 }
3028
3029 void __netif_schedule(struct Qdisc *q)
3030 {
3031         if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
3032                 __netif_reschedule(q);
3033 }
3034 EXPORT_SYMBOL(__netif_schedule);
3035
3036 struct dev_kfree_skb_cb {
3037         enum skb_free_reason reason;
3038 };
3039
3040 static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
3041 {
3042         return (struct dev_kfree_skb_cb *)skb->cb;
3043 }
3044
3045 void netif_schedule_queue(struct netdev_queue *txq)
3046 {
3047         rcu_read_lock();
3048         if (!netif_xmit_stopped(txq)) {
3049                 struct Qdisc *q = rcu_dereference(txq->qdisc);
3050
3051                 __netif_schedule(q);
3052         }
3053         rcu_read_unlock();
3054 }
3055 EXPORT_SYMBOL(netif_schedule_queue);
3056
3057 void netif_tx_wake_queue(struct netdev_queue *dev_queue)
3058 {
3059         if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
3060                 struct Qdisc *q;
3061
3062                 rcu_read_lock();
3063                 q = rcu_dereference(dev_queue->qdisc);
3064                 __netif_schedule(q);
3065                 rcu_read_unlock();
3066         }
3067 }
3068 EXPORT_SYMBOL(netif_tx_wake_queue);
3069
3070 void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
3071 {
3072         unsigned long flags;
3073
3074         if (unlikely(!skb))
3075                 return;
3076
3077         if (likely(refcount_read(&skb->users) == 1)) {
3078                 smp_rmb();
3079                 refcount_set(&skb->users, 0);
3080         } else if (likely(!refcount_dec_and_test(&skb->users))) {
3081                 return;
3082         }
3083         get_kfree_skb_cb(skb)->reason = reason;
3084         local_irq_save(flags);
3085         skb->next = __this_cpu_read(softnet_data.completion_queue);
3086         __this_cpu_write(softnet_data.completion_queue, skb);
3087         raise_softirq_irqoff(NET_TX_SOFTIRQ);
3088         local_irq_restore(flags);
3089 }
3090 EXPORT_SYMBOL(__dev_kfree_skb_irq);
3091
3092 void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
3093 {
3094         if (in_hardirq() || irqs_disabled())
3095                 __dev_kfree_skb_irq(skb, reason);
3096         else
3097                 dev_kfree_skb(skb);
3098 }
3099 EXPORT_SYMBOL(__dev_kfree_skb_any);
3100
3101
3102 /**
3103  * netif_device_detach - mark device as removed
3104  * @dev: network device
3105  *
3106  * Mark device as removed from system and therefore no longer available.
3107  */
3108 void netif_device_detach(struct net_device *dev)
3109 {
3110         if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
3111             netif_running(dev)) {
3112                 netif_tx_stop_all_queues(dev);
3113         }
3114 }
3115 EXPORT_SYMBOL(netif_device_detach);
3116
3117 /**
3118  * netif_device_attach - mark device as attached
3119  * @dev: network device
3120  *
3121  * Mark device as attached from system and restart if needed.
3122  */
3123 void netif_device_attach(struct net_device *dev)
3124 {
3125         if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
3126             netif_running(dev)) {
3127                 netif_tx_wake_all_queues(dev);
3128                 __netdev_watchdog_up(dev);
3129         }
3130 }
3131 EXPORT_SYMBOL(netif_device_attach);
3132
3133 /*
3134  * Returns a Tx hash based on the given packet descriptor a Tx queues' number
3135  * to be used as a distribution range.
3136  */
3137 static u16 skb_tx_hash(const struct net_device *dev,
3138                        const struct net_device *sb_dev,
3139                        struct sk_buff *skb)
3140 {
3141         u32 hash;
3142         u16 qoffset = 0;
3143         u16 qcount = dev->real_num_tx_queues;
3144
3145         if (dev->num_tc) {
3146                 u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
3147
3148                 qoffset = sb_dev->tc_to_txq[tc].offset;
3149                 qcount = sb_dev->tc_to_txq[tc].count;
3150                 if (unlikely(!qcount)) {
3151                         net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
3152                                              sb_dev->name, qoffset, tc);
3153                         qoffset = 0;
3154                         qcount = dev->real_num_tx_queues;
3155                 }
3156         }
3157
3158         if (skb_rx_queue_recorded(skb)) {
3159                 hash = skb_get_rx_queue(skb);
3160                 if (hash >= qoffset)
3161                         hash -= qoffset;
3162                 while (unlikely(hash >= qcount))
3163                         hash -= qcount;
3164                 return hash + qoffset;
3165         }
3166
3167         return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
3168 }
3169
3170 static void skb_warn_bad_offload(const struct sk_buff *skb)
3171 {
3172         static const netdev_features_t null_features;
3173         struct net_device *dev = skb->dev;
3174         const char *name = "";
3175
3176         if (!net_ratelimit())
3177                 return;
3178
3179         if (dev) {
3180                 if (dev->dev.parent)
3181                         name = dev_driver_string(dev->dev.parent);
3182                 else
3183                         name = netdev_name(dev);
3184         }
3185         skb_dump(KERN_WARNING, skb, false);
3186         WARN(1, "%s: caps=(%pNF, %pNF)\n",
3187              name, dev ? &dev->features : &null_features,
3188              skb->sk ? &skb->sk->sk_route_caps : &null_features);
3189 }
3190
3191 /*
3192  * Invalidate hardware checksum when packet is to be mangled, and
3193  * complete checksum manually on outgoing path.
3194  */
3195 int skb_checksum_help(struct sk_buff *skb)
3196 {
3197         __wsum csum;
3198         int ret = 0, offset;
3199
3200         if (skb->ip_summed == CHECKSUM_COMPLETE)
3201                 goto out_set_summed;
3202
3203         if (unlikely(skb_is_gso(skb))) {
3204                 skb_warn_bad_offload(skb);
3205                 return -EINVAL;
3206         }
3207
3208         /* Before computing a checksum, we should make sure no frag could
3209          * be modified by an external entity : checksum could be wrong.
3210          */
3211         if (skb_has_shared_frag(skb)) {
3212                 ret = __skb_linearize(skb);
3213                 if (ret)
3214                         goto out;
3215         }
3216
3217         offset = skb_checksum_start_offset(skb);
3218         BUG_ON(offset >= skb_headlen(skb));
3219         csum = skb_checksum(skb, offset, skb->len - offset, 0);
3220
3221         offset += skb->csum_offset;
3222         BUG_ON(offset + sizeof(__sum16) > skb_headlen(skb));
3223
3224         ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
3225         if (ret)
3226                 goto out;
3227
3228         *(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
3229 out_set_summed:
3230         skb->ip_summed = CHECKSUM_NONE;
3231 out:
3232         return ret;
3233 }
3234 EXPORT_SYMBOL(skb_checksum_help);
3235
3236 int skb_crc32c_csum_help(struct sk_buff *skb)
3237 {
3238         __le32 crc32c_csum;
3239         int ret = 0, offset, start;
3240
3241         if (skb->ip_summed != CHECKSUM_PARTIAL)
3242                 goto out;
3243
3244         if (unlikely(skb_is_gso(skb)))
3245                 goto out;
3246
3247         /* Before computing a checksum, we should make sure no frag could
3248          * be modified by an external entity : checksum could be wrong.
3249          */
3250         if (unlikely(skb_has_shared_frag(skb))) {
3251                 ret = __skb_linearize(skb);
3252                 if (ret)
3253                         goto out;
3254         }
3255         start = skb_checksum_start_offset(skb);
3256         offset = start + offsetof(struct sctphdr, checksum);
3257         if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
3258                 ret = -EINVAL;
3259                 goto out;
3260         }
3261
3262         ret = skb_ensure_writable(skb, offset + sizeof(__le32));
3263         if (ret)
3264                 goto out;
3265
3266         crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
3267                                                   skb->len - start, ~(__u32)0,
3268                                                   crc32c_csum_stub));
3269         *(__le32 *)(skb->data + offset) = crc32c_csum;
3270         skb->ip_summed = CHECKSUM_NONE;
3271         skb->csum_not_inet = 0;
3272 out:
3273         return ret;
3274 }
3275
3276 __be16 skb_network_protocol(struct sk_buff *skb, int *depth)
3277 {
3278         __be16 type = skb->protocol;
3279
3280         /* Tunnel gso handlers can set protocol to ethernet. */
3281         if (type == htons(ETH_P_TEB)) {
3282                 struct ethhdr *eth;
3283
3284                 if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
3285                         return 0;
3286
3287                 eth = (struct ethhdr *)skb->data;
3288                 type = eth->h_proto;
3289         }
3290
3291         return __vlan_get_protocol(skb, type, depth);
3292 }
3293
3294 /* openvswitch calls this on rx path, so we need a different check.
3295  */
3296 static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
3297 {
3298         if (tx_path)
3299                 return skb->ip_summed != CHECKSUM_PARTIAL &&
3300                        skb->ip_summed != CHECKSUM_UNNECESSARY;
3301
3302         return skb->ip_summed == CHECKSUM_NONE;
3303 }
3304
3305 /**
3306  *      __skb_gso_segment - Perform segmentation on skb.
3307  *      @skb: buffer to segment
3308  *      @features: features for the output path (see dev->features)
3309  *      @tx_path: whether it is called in TX path
3310  *
3311  *      This function segments the given skb and returns a list of segments.
3312  *
3313  *      It may return NULL if the skb requires no segmentation.  This is
3314  *      only possible when GSO is used for verifying header integrity.
3315  *
3316  *      Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
3317  */
3318 struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
3319                                   netdev_features_t features, bool tx_path)
3320 {
3321         struct sk_buff *segs;
3322
3323         if (unlikely(skb_needs_check(skb, tx_path))) {
3324                 int err;
3325
3326                 /* We're going to init ->check field in TCP or UDP header */
3327                 err = skb_cow_head(skb, 0);
3328                 if (err < 0)
3329                         return ERR_PTR(err);
3330         }
3331
3332         /* Only report GSO partial support if it will enable us to
3333          * support segmentation on this frame without needing additional
3334          * work.
3335          */
3336         if (features & NETIF_F_GSO_PARTIAL) {
3337                 netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
3338                 struct net_device *dev = skb->dev;
3339
3340                 partial_features |= dev->features & dev->gso_partial_features;
3341                 if (!skb_gso_ok(skb, features | partial_features))
3342                         features &= ~NETIF_F_GSO_PARTIAL;
3343         }
3344
3345         BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
3346                      sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
3347
3348         SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
3349         SKB_GSO_CB(skb)->encap_level = 0;
3350
3351         skb_reset_mac_header(skb);
3352         skb_reset_mac_len(skb);
3353
3354         segs = skb_mac_gso_segment(skb, features);
3355
3356         if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
3357                 skb_warn_bad_offload(skb);
3358
3359         return segs;
3360 }
3361 EXPORT_SYMBOL(__skb_gso_segment);
3362
3363 /* Take action when hardware reception checksum errors are detected. */
3364 #ifdef CONFIG_BUG
3365 static void do_netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3366 {
3367         netdev_err(dev, "hw csum failure\n");
3368         skb_dump(KERN_ERR, skb, true);
3369         dump_stack();
3370 }
3371
3372 void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
3373 {
3374         DO_ONCE_LITE(do_netdev_rx_csum_fault, dev, skb);
3375 }
3376 EXPORT_SYMBOL(netdev_rx_csum_fault);
3377 #endif
3378
3379 /* XXX: check that highmem exists at all on the given machine. */
3380 static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
3381 {
3382 #ifdef CONFIG_HIGHMEM
3383         int i;
3384
3385         if (!(dev->features & NETIF_F_HIGHDMA)) {
3386                 for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
3387                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
3388
3389                         if (PageHighMem(skb_frag_page(frag)))
3390                                 return 1;
3391                 }
3392         }
3393 #endif
3394         return 0;
3395 }
3396
3397 /* If MPLS offload request, verify we are testing hardware MPLS features
3398  * instead of standard features for the netdev.
3399  */
3400 #if IS_ENABLED(CONFIG_NET_MPLS_GSO)
3401 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3402                                            netdev_features_t features,
3403                                            __be16 type)
3404 {
3405         if (eth_p_mpls(type))
3406                 features &= skb->dev->mpls_features;
3407
3408         return features;
3409 }
3410 #else
3411 static netdev_features_t net_mpls_features(struct sk_buff *skb,
3412                                            netdev_features_t features,
3413                                            __be16 type)
3414 {
3415         return features;
3416 }
3417 #endif
3418
3419 static netdev_features_t harmonize_features(struct sk_buff *skb,
3420         netdev_features_t features)
3421 {
3422         __be16 type;
3423
3424         type = skb_network_protocol(skb, NULL);
3425         features = net_mpls_features(skb, features, type);
3426
3427         if (skb->ip_summed != CHECKSUM_NONE &&
3428             !can_checksum_protocol(features, type)) {
3429                 features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
3430         }
3431         if (illegal_highdma(skb->dev, skb))
3432                 features &= ~NETIF_F_SG;
3433
3434         return features;
3435 }
3436
3437 netdev_features_t passthru_features_check(struct sk_buff *skb,
3438                                           struct net_device *dev,
3439                                           netdev_features_t features)
3440 {
3441         return features;
3442 }
3443 EXPORT_SYMBOL(passthru_features_check);
3444
3445 static netdev_features_t dflt_features_check(struct sk_buff *skb,
3446                                              struct net_device *dev,
3447                                              netdev_features_t features)
3448 {
3449         return vlan_features_check(skb, features);
3450 }
3451
3452 static netdev_features_t gso_features_check(const struct sk_buff *skb,
3453                                             struct net_device *dev,
3454                                             netdev_features_t features)
3455 {
3456         u16 gso_segs = skb_shinfo(skb)->gso_segs;
3457
3458         if (gso_segs > READ_ONCE(dev->gso_max_segs))
3459                 return features & ~NETIF_F_GSO_MASK;
3460
3461         if (!skb_shinfo(skb)->gso_type) {
3462                 skb_warn_bad_offload(skb);
3463                 return features & ~NETIF_F_GSO_MASK;
3464         }
3465
3466         /* Support for GSO partial features requires software
3467          * intervention before we can actually process the packets
3468          * so we need to strip support for any partial features now
3469          * and we can pull them back in after we have partially
3470          * segmented the frame.
3471          */
3472         if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
3473                 features &= ~dev->gso_partial_features;
3474
3475         /* Make sure to clear the IPv4 ID mangling feature if the
3476          * IPv4 header has the potential to be fragmented.
3477          */
3478         if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
3479                 struct iphdr *iph = skb->encapsulation ?
3480                                     inner_ip_hdr(skb) : ip_hdr(skb);
3481
3482                 if (!(iph->frag_off & htons(IP_DF)))
3483                         features &= ~NETIF_F_TSO_MANGLEID;
3484         }
3485
3486         return features;
3487 }
3488
3489 netdev_features_t netif_skb_features(struct sk_buff *skb)
3490 {
3491         struct net_device *dev = skb->dev;
3492         netdev_features_t features = dev->features;
3493
3494         if (skb_is_gso(skb))
3495                 features = gso_features_check(skb, dev, features);
3496
3497         /* If encapsulation offload request, verify we are testing
3498          * hardware encapsulation features instead of standard
3499          * features for the netdev
3500          */
3501         if (skb->encapsulation)
3502                 features &= dev->hw_enc_features;
3503
3504         if (skb_vlan_tagged(skb))
3505                 features = netdev_intersect_features(features,
3506                                                      dev->vlan_features |
3507                                                      NETIF_F_HW_VLAN_CTAG_TX |
3508                                                      NETIF_F_HW_VLAN_STAG_TX);
3509
3510         if (dev->netdev_ops->ndo_features_check)
3511                 features &= dev->netdev_ops->ndo_features_check(skb, dev,
3512                                                                 features);
3513         else
3514                 features &= dflt_features_check(skb, dev, features);
3515
3516         return harmonize_features(skb, features);
3517 }
3518 EXPORT_SYMBOL(netif_skb_features);
3519
3520 static int xmit_one(struct sk_buff *skb, struct net_device *dev,
3521                     struct netdev_queue *txq, bool more)
3522 {
3523         unsigned int len;
3524         int rc;
3525
3526         if (dev_nit_active(dev))
3527                 dev_queue_xmit_nit(skb, dev);
3528
3529         len = skb->len;
3530         PRANDOM_ADD_NOISE(skb, dev, txq, len + jiffies);
3531         trace_net_dev_start_xmit(skb, dev);
3532         rc = netdev_start_xmit(skb, dev, txq, more);
3533         trace_net_dev_xmit(skb, rc, dev, len);
3534
3535         return rc;
3536 }
3537
3538 struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
3539                                     struct netdev_queue *txq, int *ret)
3540 {
3541         struct sk_buff *skb = first;
3542         int rc = NETDEV_TX_OK;
3543
3544         while (skb) {
3545                 struct sk_buff *next = skb->next;
3546
3547                 skb_mark_not_on_list(skb);
3548                 rc = xmit_one(skb, dev, txq, next != NULL);
3549                 if (unlikely(!dev_xmit_complete(rc))) {
3550                         skb->next = next;
3551                         goto out;
3552                 }
3553
3554                 skb = next;
3555                 if (netif_tx_queue_stopped(txq) && skb) {
3556                         rc = NETDEV_TX_BUSY;
3557                         break;
3558                 }
3559         }
3560
3561 out:
3562         *ret = rc;
3563         return skb;
3564 }
3565
3566 static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
3567                                           netdev_features_t features)
3568 {
3569         if (skb_vlan_tag_present(skb) &&
3570             !vlan_hw_offload_capable(features, skb->vlan_proto))
3571                 skb = __vlan_hwaccel_push_inside(skb);
3572         return skb;
3573 }
3574
3575 int skb_csum_hwoffload_help(struct sk_buff *skb,
3576                             const netdev_features_t features)
3577 {
3578         if (unlikely(skb_csum_is_sctp(skb)))
3579                 return !!(features & NETIF_F_SCTP_CRC) ? 0 :
3580                         skb_crc32c_csum_help(skb);
3581
3582         if (features & NETIF_F_HW_CSUM)
3583                 return 0;
3584
3585         if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
3586                 switch (skb->csum_offset) {
3587                 case offsetof(struct tcphdr, check):
3588                 case offsetof(struct udphdr, check):
3589                         return 0;
3590                 }
3591         }
3592
3593         return skb_checksum_help(skb);
3594 }
3595 EXPORT_SYMBOL(skb_csum_hwoffload_help);
3596
3597 static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
3598 {
3599         netdev_features_t features;
3600
3601         features = netif_skb_features(skb);
3602         skb = validate_xmit_vlan(skb, features);
3603         if (unlikely(!skb))
3604                 goto out_null;
3605
3606         skb = sk_validate_xmit_skb(skb, dev);
3607         if (unlikely(!skb))
3608                 goto out_null;
3609
3610         if (netif_needs_gso(skb, features)) {
3611                 struct sk_buff *segs;
3612
3613                 segs = skb_gso_segment(skb, features);
3614                 if (IS_ERR(segs)) {
3615                         goto out_kfree_skb;
3616                 } else if (segs) {
3617                         consume_skb(skb);
3618                         skb = segs;
3619                 }
3620         } else {
3621                 if (skb_needs_linearize(skb, features) &&
3622                     __skb_linearize(skb))
3623                         goto out_kfree_skb;
3624
3625                 /* If packet is not checksummed and device does not
3626                  * support checksumming for this protocol, complete
3627                  * checksumming here.
3628                  */
3629                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
3630                         if (skb->encapsulation)
3631                                 skb_set_inner_transport_header(skb,
3632                                                                skb_checksum_start_offset(skb));
3633                         else
3634                                 skb_set_transport_header(skb,
3635                                                          skb_checksum_start_offset(skb));
3636                         if (skb_csum_hwoffload_help(skb, features))
3637                                 goto out_kfree_skb;
3638                 }
3639         }
3640
3641         skb = validate_xmit_xfrm(skb, features, again);
3642
3643         return skb;
3644
3645 out_kfree_skb:
3646         kfree_skb(skb);
3647 out_null:
3648         dev_core_stats_tx_dropped_inc(dev);
3649         return NULL;
3650 }
3651
3652 struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
3653 {
3654         struct sk_buff *next, *head = NULL, *tail;
3655
3656         for (; skb != NULL; skb = next) {
3657                 next = skb->next;
3658                 skb_mark_not_on_list(skb);
3659
3660                 /* in case skb wont be segmented, point to itself */
3661                 skb->prev = skb;
3662
3663                 skb = validate_xmit_skb(skb, dev, again);
3664                 if (!skb)
3665                         continue;
3666
3667                 if (!head)
3668                         head = skb;
3669                 else
3670                         tail->next = skb;
3671                 /* If skb was segmented, skb->prev points to
3672                  * the last segment. If not, it still contains skb.
3673                  */
3674                 tail = skb->prev;
3675         }
3676         return head;
3677 }
3678 EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
3679
3680 static void qdisc_pkt_len_init(struct sk_buff *skb)
3681 {
3682         const struct skb_shared_info *shinfo = skb_shinfo(skb);
3683
3684         qdisc_skb_cb(skb)->pkt_len = skb->len;
3685
3686         /* To get more precise estimation of bytes sent on wire,
3687          * we add to pkt_len the headers size of all segments
3688          */
3689         if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
3690                 unsigned int hdr_len;
3691                 u16 gso_segs = shinfo->gso_segs;
3692
3693                 /* mac layer + network layer */
3694                 hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
3695
3696                 /* + transport layer */
3697                 if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
3698                         const struct tcphdr *th;
3699                         struct tcphdr _tcphdr;
3700
3701                         th = skb_header_pointer(skb, skb_transport_offset(skb),
3702                                                 sizeof(_tcphdr), &_tcphdr);
3703                         if (likely(th))
3704                                 hdr_len += __tcp_hdrlen(th);
3705                 } else {
3706                         struct udphdr _udphdr;
3707
3708                         if (skb_header_pointer(skb, skb_transport_offset(skb),
3709                                                sizeof(_udphdr), &_udphdr))
3710                                 hdr_len += sizeof(struct udphdr);
3711                 }
3712
3713                 if (shinfo->gso_type & SKB_GSO_DODGY)
3714                         gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
3715                                                 shinfo->gso_size);
3716
3717                 qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
3718         }
3719 }
3720
3721 static int dev_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *q,
3722                              struct sk_buff **to_free,
3723                              struct netdev_queue *txq)
3724 {
3725         int rc;
3726
3727         rc = q->enqueue(skb, q, to_free) & NET_XMIT_MASK;
3728         if (rc == NET_XMIT_SUCCESS)
3729                 trace_qdisc_enqueue(q, txq, skb);
3730         return rc;
3731 }
3732
3733 static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
3734                                  struct net_device *dev,
3735                                  struct netdev_queue *txq)
3736 {
3737         spinlock_t *root_lock = qdisc_lock(q);
3738         struct sk_buff *to_free = NULL;
3739         bool contended;
3740         int rc;
3741
3742         qdisc_calculate_pkt_len(skb, q);
3743
3744         if (q->flags & TCQ_F_NOLOCK) {
3745                 if (q->flags & TCQ_F_CAN_BYPASS && nolock_qdisc_is_empty(q) &&
3746                     qdisc_run_begin(q)) {
3747                         /* Retest nolock_qdisc_is_empty() within the protection
3748                          * of q->seqlock to protect from racing with requeuing.
3749                          */
3750                         if (unlikely(!nolock_qdisc_is_empty(q))) {
3751                                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3752                                 __qdisc_run(q);
3753                                 qdisc_run_end(q);
3754
3755                                 goto no_lock_out;
3756                         }
3757
3758                         qdisc_bstats_cpu_update(q, skb);
3759                         if (sch_direct_xmit(skb, q, dev, txq, NULL, true) &&
3760                             !nolock_qdisc_is_empty(q))
3761                                 __qdisc_run(q);
3762
3763                         qdisc_run_end(q);
3764                         return NET_XMIT_SUCCESS;
3765                 }
3766
3767                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3768                 qdisc_run(q);
3769
3770 no_lock_out:
3771                 if (unlikely(to_free))
3772                         kfree_skb_list_reason(to_free,
3773                                               SKB_DROP_REASON_QDISC_DROP);
3774                 return rc;
3775         }
3776
3777         /*
3778          * Heuristic to force contended enqueues to serialize on a
3779          * separate lock before trying to get qdisc main lock.
3780          * This permits qdisc->running owner to get the lock more
3781          * often and dequeue packets faster.
3782          * On PREEMPT_RT it is possible to preempt the qdisc owner during xmit
3783          * and then other tasks will only enqueue packets. The packets will be
3784          * sent after the qdisc owner is scheduled again. To prevent this
3785          * scenario the task always serialize on the lock.
3786          */
3787         contended = qdisc_is_running(q) || IS_ENABLED(CONFIG_PREEMPT_RT);
3788         if (unlikely(contended))
3789                 spin_lock(&q->busylock);
3790
3791         spin_lock(root_lock);
3792         if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
3793                 __qdisc_drop(skb, &to_free);
3794                 rc = NET_XMIT_DROP;
3795         } else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
3796                    qdisc_run_begin(q)) {
3797                 /*
3798                  * This is a work-conserving queue; there are no old skbs
3799                  * waiting to be sent out; and the qdisc is not running -
3800                  * xmit the skb directly.
3801                  */
3802
3803                 qdisc_bstats_update(q, skb);
3804
3805                 if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
3806                         if (unlikely(contended)) {
3807                                 spin_unlock(&q->busylock);
3808                                 contended = false;
3809                         }
3810                         __qdisc_run(q);
3811                 }
3812
3813                 qdisc_run_end(q);
3814                 rc = NET_XMIT_SUCCESS;
3815         } else {
3816                 rc = dev_qdisc_enqueue(skb, q, &to_free, txq);
3817                 if (qdisc_run_begin(q)) {
3818                         if (unlikely(contended)) {
3819                                 spin_unlock(&q->busylock);
3820                                 contended = false;
3821                         }
3822                         __qdisc_run(q);
3823                         qdisc_run_end(q);
3824                 }
3825         }
3826         spin_unlock(root_lock);
3827         if (unlikely(to_free))
3828                 kfree_skb_list_reason(to_free, SKB_DROP_REASON_QDISC_DROP);
3829         if (unlikely(contended))
3830                 spin_unlock(&q->busylock);
3831         return rc;
3832 }
3833
3834 #if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
3835 static void skb_update_prio(struct sk_buff *skb)
3836 {
3837         const struct netprio_map *map;
3838         const struct sock *sk;
3839         unsigned int prioidx;
3840
3841         if (skb->priority)
3842                 return;
3843         map = rcu_dereference_bh(skb->dev->priomap);
3844         if (!map)
3845                 return;
3846         sk = skb_to_full_sk(skb);
3847         if (!sk)
3848                 return;
3849
3850         prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
3851
3852         if (prioidx < map->priomap_len)
3853                 skb->priority = map->priomap[prioidx];
3854 }
3855 #else
3856 #define skb_update_prio(skb)
3857 #endif
3858
3859 /**
3860  *      dev_loopback_xmit - loop back @skb
3861  *      @net: network namespace this loopback is happening in
3862  *      @sk:  sk needed to be a netfilter okfn
3863  *      @skb: buffer to transmit
3864  */
3865 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
3866 {
3867         skb_reset_mac_header(skb);
3868         __skb_pull(skb, skb_network_offset(skb));
3869         skb->pkt_type = PACKET_LOOPBACK;
3870         if (skb->ip_summed == CHECKSUM_NONE)
3871                 skb->ip_summed = CHECKSUM_UNNECESSARY;
3872         WARN_ON(!skb_dst(skb));
3873         skb_dst_force(skb);
3874         netif_rx(skb);
3875         return 0;
3876 }
3877 EXPORT_SYMBOL(dev_loopback_xmit);
3878
3879 #ifdef CONFIG_NET_EGRESS
3880 static struct sk_buff *
3881 sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
3882 {
3883 #ifdef CONFIG_NET_CLS_ACT
3884         struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
3885         struct tcf_result cl_res;
3886
3887         if (!miniq)
3888                 return skb;
3889
3890         /* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
3891         tc_skb_cb(skb)->mru = 0;
3892         tc_skb_cb(skb)->post_ct = false;
3893         mini_qdisc_bstats_cpu_update(miniq, skb);
3894
3895         switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
3896         case TC_ACT_OK:
3897         case TC_ACT_RECLASSIFY:
3898                 skb->tc_index = TC_H_MIN(cl_res.classid);
3899                 break;
3900         case TC_ACT_SHOT:
3901                 mini_qdisc_qstats_cpu_drop(miniq);
3902                 *ret = NET_XMIT_DROP;
3903                 kfree_skb_reason(skb, SKB_DROP_REASON_TC_EGRESS);
3904                 return NULL;
3905         case TC_ACT_STOLEN:
3906         case TC_ACT_QUEUED:
3907         case TC_ACT_TRAP:
3908                 *ret = NET_XMIT_SUCCESS;
3909                 consume_skb(skb);
3910                 return NULL;
3911         case TC_ACT_REDIRECT:
3912                 /* No need to push/pop skb's mac_header here on egress! */
3913                 skb_do_redirect(skb);
3914                 *ret = NET_XMIT_SUCCESS;
3915                 return NULL;
3916         default:
3917                 break;
3918         }
3919 #endif /* CONFIG_NET_CLS_ACT */
3920
3921         return skb;
3922 }
3923 #endif /* CONFIG_NET_EGRESS */
3924
3925 #ifdef CONFIG_XPS
3926 static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
3927                                struct xps_dev_maps *dev_maps, unsigned int tci)
3928 {
3929         int tc = netdev_get_prio_tc_map(dev, skb->priority);
3930         struct xps_map *map;
3931         int queue_index = -1;
3932
3933         if (tc >= dev_maps->num_tc || tci >= dev_maps->nr_ids)
3934                 return queue_index;
3935
3936         tci *= dev_maps->num_tc;
3937         tci += tc;
3938
3939         map = rcu_dereference(dev_maps->attr_map[tci]);
3940         if (map) {
3941                 if (map->len == 1)
3942                         queue_index = map->queues[0];
3943                 else
3944                         queue_index = map->queues[reciprocal_scale(
3945                                                 skb_get_hash(skb), map->len)];
3946                 if (unlikely(queue_index >= dev->real_num_tx_queues))
3947                         queue_index = -1;
3948         }
3949         return queue_index;
3950 }
3951 #endif
3952
3953 static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
3954                          struct sk_buff *skb)
3955 {
3956 #ifdef CONFIG_XPS
3957         struct xps_dev_maps *dev_maps;
3958         struct sock *sk = skb->sk;
3959         int queue_index = -1;
3960
3961         if (!static_key_false(&xps_needed))
3962                 return -1;
3963
3964         rcu_read_lock();
3965         if (!static_key_false(&xps_rxqs_needed))
3966                 goto get_cpus_map;
3967
3968         dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_RXQS]);
3969         if (dev_maps) {
3970                 int tci = sk_rx_queue_get(sk);
3971
3972                 if (tci >= 0)
3973                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
3974                                                           tci);
3975         }
3976
3977 get_cpus_map:
3978         if (queue_index < 0) {
3979                 dev_maps = rcu_dereference(sb_dev->xps_maps[XPS_CPUS]);
3980                 if (dev_maps) {
3981                         unsigned int tci = skb->sender_cpu - 1;
3982
3983                         queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
3984                                                           tci);
3985                 }
3986         }
3987         rcu_read_unlock();
3988
3989         return queue_index;
3990 #else
3991         return -1;
3992 #endif
3993 }
3994
3995 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
3996                      struct net_device *sb_dev)
3997 {
3998         return 0;
3999 }
4000 EXPORT_SYMBOL(dev_pick_tx_zero);
4001
4002 u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
4003                        struct net_device *sb_dev)
4004 {
4005         return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
4006 }
4007 EXPORT_SYMBOL(dev_pick_tx_cpu_id);
4008
4009 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
4010                      struct net_device *sb_dev)
4011 {
4012         struct sock *sk = skb->sk;
4013         int queue_index = sk_tx_queue_get(sk);
4014
4015         sb_dev = sb_dev ? : dev;
4016
4017         if (queue_index < 0 || skb->ooo_okay ||
4018             queue_index >= dev->real_num_tx_queues) {
4019                 int new_index = get_xps_queue(dev, sb_dev, skb);
4020
4021                 if (new_index < 0)
4022                         new_index = skb_tx_hash(dev, sb_dev, skb);
4023
4024                 if (queue_index != new_index && sk &&
4025                     sk_fullsock(sk) &&
4026                     rcu_access_pointer(sk->sk_dst_cache))
4027                         sk_tx_queue_set(sk, new_index);
4028
4029                 queue_index = new_index;
4030         }
4031
4032         return queue_index;
4033 }
4034 EXPORT_SYMBOL(netdev_pick_tx);
4035
4036 struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
4037                                          struct sk_buff *skb,
4038                                          struct net_device *sb_dev)
4039 {
4040         int queue_index = 0;
4041
4042 #ifdef CONFIG_XPS
4043         u32 sender_cpu = skb->sender_cpu - 1;
4044
4045         if (sender_cpu >= (u32)NR_CPUS)
4046                 skb->sender_cpu = raw_smp_processor_id() + 1;
4047 #endif
4048
4049         if (dev->real_num_tx_queues != 1) {
4050                 const struct net_device_ops *ops = dev->netdev_ops;
4051
4052                 if (ops->ndo_select_queue)
4053                         queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
4054                 else
4055                         queue_index = netdev_pick_tx(dev, skb, sb_dev);
4056
4057                 queue_index = netdev_cap_txqueue(dev, queue_index);
4058         }
4059
4060         skb_set_queue_mapping(skb, queue_index);
4061         return netdev_get_tx_queue(dev, queue_index);
4062 }
4063
4064 /**
4065  *      __dev_queue_xmit - transmit a buffer
4066  *      @skb: buffer to transmit
4067  *      @sb_dev: suboordinate device used for L2 forwarding offload
4068  *
4069  *      Queue a buffer for transmission to a network device. The caller must
4070  *      have set the device and priority and built the buffer before calling
4071  *      this function. The function can be called from an interrupt.
4072  *
4073  *      A negative errno code is returned on a failure. A success does not
4074  *      guarantee the frame will be transmitted as it may be dropped due
4075  *      to congestion or traffic shaping.
4076  *
4077  * -----------------------------------------------------------------------------------
4078  *      I notice this method can also return errors from the queue disciplines,
4079  *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
4080  *      be positive.
4081  *
4082  *      Regardless of the return value, the skb is consumed, so it is currently
4083  *      difficult to retry a send to this method.  (You can bump the ref count
4084  *      before sending to hold a reference for retry if you are careful.)
4085  *
4086  *      When calling this method, interrupts MUST be enabled.  This is because
4087  *      the BH enable code must have IRQs enabled so that it will not deadlock.
4088  *          --BLG
4089  */
4090 static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
4091 {
4092         struct net_device *dev = skb->dev;
4093         struct netdev_queue *txq;
4094         struct Qdisc *q;
4095         int rc = -ENOMEM;
4096         bool again = false;
4097
4098         skb_reset_mac_header(skb);
4099
4100         if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
4101                 __skb_tstamp_tx(skb, NULL, NULL, skb->sk, SCM_TSTAMP_SCHED);
4102
4103         /* Disable soft irqs for various locks below. Also
4104          * stops preemption for RCU.
4105          */
4106         rcu_read_lock_bh();
4107
4108         skb_update_prio(skb);
4109
4110         qdisc_pkt_len_init(skb);
4111 #ifdef CONFIG_NET_CLS_ACT
4112         skb->tc_at_ingress = 0;
4113 #endif
4114 #ifdef CONFIG_NET_EGRESS
4115         if (static_branch_unlikely(&egress_needed_key)) {
4116                 if (nf_hook_egress_active()) {
4117                         skb = nf_hook_egress(skb, &rc, dev);
4118                         if (!skb)
4119                                 goto out;
4120                 }
4121                 nf_skip_egress(skb, true);
4122                 skb = sch_handle_egress(skb, &rc, dev);
4123                 if (!skb)
4124                         goto out;
4125                 nf_skip_egress(skb, false);
4126         }
4127 #endif
4128         /* If device/qdisc don't need skb->dst, release it right now while
4129          * its hot in this cpu cache.
4130          */
4131         if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
4132                 skb_dst_drop(skb);
4133         else
4134                 skb_dst_force(skb);
4135
4136         txq = netdev_core_pick_tx(dev, skb, sb_dev);
4137         q = rcu_dereference_bh(txq->qdisc);
4138
4139         trace_net_dev_queue(skb);
4140         if (q->enqueue) {
4141                 rc = __dev_xmit_skb(skb, q, dev, txq);
4142                 goto out;
4143         }
4144
4145         /* The device has no queue. Common case for software devices:
4146          * loopback, all the sorts of tunnels...
4147
4148          * Really, it is unlikely that netif_tx_lock protection is necessary
4149          * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
4150          * counters.)
4151          * However, it is possible, that they rely on protection
4152          * made by us here.
4153
4154          * Check this and shot the lock. It is not prone from deadlocks.
4155          *Either shot noqueue qdisc, it is even simpler 8)
4156          */
4157         if (dev->flags & IFF_UP) {
4158                 int cpu = smp_processor_id(); /* ok because BHs are off */
4159
4160                 /* Other cpus might concurrently change txq->xmit_lock_owner
4161                  * to -1 or to their cpu id, but not to our id.
4162                  */
4163                 if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
4164                         if (dev_xmit_recursion())
4165                                 goto recursion_alert;
4166
4167                         skb = validate_xmit_skb(skb, dev, &again);
4168                         if (!skb)
4169                                 goto out;
4170
4171                         PRANDOM_ADD_NOISE(skb, dev, txq, jiffies);
4172                         HARD_TX_LOCK(dev, txq, cpu);
4173
4174                         if (!netif_xmit_stopped(txq)) {
4175                                 dev_xmit_recursion_inc();
4176                                 skb = dev_hard_start_xmit(skb, dev, txq, &rc);
4177                                 dev_xmit_recursion_dec();
4178                                 if (dev_xmit_complete(rc)) {
4179                                         HARD_TX_UNLOCK(dev, txq);
4180                                         goto out;
4181                                 }
4182                         }
4183                         HARD_TX_UNLOCK(dev, txq);
4184                         net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
4185                                              dev->name);
4186                 } else {
4187                         /* Recursion is detected! It is possible,
4188                          * unfortunately
4189                          */
4190 recursion_alert:
4191                         net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
4192                                              dev->name);
4193                 }
4194         }
4195
4196         rc = -ENETDOWN;
4197         rcu_read_unlock_bh();
4198
4199         dev_core_stats_tx_dropped_inc(dev);
4200         kfree_skb_list(skb);
4201         return rc;
4202 out:
4203         rcu_read_unlock_bh();
4204         return rc;
4205 }
4206
4207 int dev_queue_xmit(struct sk_buff *skb)
4208 {
4209         return __dev_queue_xmit(skb, NULL);
4210 }
4211 EXPORT_SYMBOL(dev_queue_xmit);
4212
4213 int dev_queue_xmit_accel(struct sk_buff *skb, struct net_device *sb_dev)
4214 {
4215         return __dev_queue_xmit(skb, sb_dev);
4216 }
4217 EXPORT_SYMBOL(dev_queue_xmit_accel);
4218
4219 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
4220 {
4221         struct net_device *dev = skb->dev;
4222         struct sk_buff *orig_skb = skb;
4223         struct netdev_queue *txq;
4224         int ret = NETDEV_TX_BUSY;
4225         bool again = false;
4226
4227         if (unlikely(!netif_running(dev) ||
4228                      !netif_carrier_ok(dev)))
4229                 goto drop;
4230
4231         skb = validate_xmit_skb_list(skb, dev, &again);
4232         if (skb != orig_skb)
4233                 goto drop;
4234
4235         skb_set_queue_mapping(skb, queue_id);
4236         txq = skb_get_tx_queue(dev, skb);
4237         PRANDOM_ADD_NOISE(skb, dev, txq, jiffies);
4238
4239         local_bh_disable();
4240
4241         dev_xmit_recursion_inc();
4242         HARD_TX_LOCK(dev, txq, smp_processor_id());
4243         if (!netif_xmit_frozen_or_drv_stopped(txq))
4244                 ret = netdev_start_xmit(skb, dev, txq, false);
4245         HARD_TX_UNLOCK(dev, txq);
4246         dev_xmit_recursion_dec();
4247
4248         local_bh_enable();
4249         return ret;
4250 drop:
4251         dev_core_stats_tx_dropped_inc(dev);
4252         kfree_skb_list(skb);
4253         return NET_XMIT_DROP;
4254 }
4255 EXPORT_SYMBOL(__dev_direct_xmit);
4256
4257 /*************************************************************************
4258  *                      Receiver routines
4259  *************************************************************************/
4260
4261 int netdev_max_backlog __read_mostly = 1000;
4262 EXPORT_SYMBOL(netdev_max_backlog);
4263
4264 int netdev_tstamp_prequeue __read_mostly = 1;
4265 int netdev_budget __read_mostly = 300;
4266 /* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
4267 unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
4268 int weight_p __read_mostly = 64;           /* old backlog weight */
4269 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
4270 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
4271 int dev_rx_weight __read_mostly = 64;
4272 int dev_tx_weight __read_mostly = 64;
4273
4274 /* Called with irq disabled */
4275 static inline void ____napi_schedule(struct softnet_data *sd,
4276                                      struct napi_struct *napi)
4277 {
4278         struct task_struct *thread;
4279
4280         lockdep_assert_irqs_disabled();
4281
4282         if (test_bit(NAPI_STATE_THREADED, &napi->state)) {
4283                 /* Paired with smp_mb__before_atomic() in
4284                  * napi_enable()/dev_set_threaded().
4285                  * Use READ_ONCE() to guarantee a complete
4286                  * read on napi->thread. Only call
4287                  * wake_up_process() when it's not NULL.
4288                  */
4289                 thread = READ_ONCE(napi->thread);
4290                 if (thread) {
4291                         /* Avoid doing set_bit() if the thread is in
4292                          * INTERRUPTIBLE state, cause napi_thread_wait()
4293                          * makes sure to proceed with napi polling
4294                          * if the thread is explicitly woken from here.
4295                          */
4296                         if (READ_ONCE(thread->__state) != TASK_INTERRUPTIBLE)
4297                                 set_bit(NAPI_STATE_SCHED_THREADED, &napi->state);
4298                         wake_up_process(thread);
4299                         return;
4300                 }
4301         }
4302
4303         list_add_tail(&napi->poll_list, &sd->poll_list);
4304         __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4305 }
4306
4307 #ifdef CONFIG_RPS
4308
4309 /* One global table that all flow-based protocols share. */
4310 struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
4311 EXPORT_SYMBOL(rps_sock_flow_table);
4312 u32 rps_cpu_mask __read_mostly;
4313 EXPORT_SYMBOL(rps_cpu_mask);
4314
4315 struct static_key_false rps_needed __read_mostly;
4316 EXPORT_SYMBOL(rps_needed);
4317 struct static_key_false rfs_needed __read_mostly;
4318 EXPORT_SYMBOL(rfs_needed);
4319
4320 static struct rps_dev_flow *
4321 set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4322             struct rps_dev_flow *rflow, u16 next_cpu)
4323 {
4324         if (next_cpu < nr_cpu_ids) {
4325 #ifdef CONFIG_RFS_ACCEL
4326                 struct netdev_rx_queue *rxqueue;
4327                 struct rps_dev_flow_table *flow_table;
4328                 struct rps_dev_flow *old_rflow;
4329                 u32 flow_id;
4330                 u16 rxq_index;
4331                 int rc;
4332
4333                 /* Should we steer this flow to a different hardware queue? */
4334                 if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
4335                     !(dev->features & NETIF_F_NTUPLE))
4336                         goto out;
4337                 rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
4338                 if (rxq_index == skb_get_rx_queue(skb))
4339                         goto out;
4340
4341                 rxqueue = dev->_rx + rxq_index;
4342                 flow_table = rcu_dereference(rxqueue->rps_flow_table);
4343                 if (!flow_table)
4344                         goto out;
4345                 flow_id = skb_get_hash(skb) & flow_table->mask;
4346                 rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
4347                                                         rxq_index, flow_id);
4348                 if (rc < 0)
4349                         goto out;
4350                 old_rflow = rflow;
4351                 rflow = &flow_table->flows[flow_id];
4352                 rflow->filter = rc;
4353                 if (old_rflow->filter == rflow->filter)
4354                         old_rflow->filter = RPS_NO_FILTER;
4355         out:
4356 #endif
4357                 rflow->last_qtail =
4358                         per_cpu(softnet_data, next_cpu).input_queue_head;
4359         }
4360
4361         rflow->cpu = next_cpu;
4362         return rflow;
4363 }
4364
4365 /*
4366  * get_rps_cpu is called from netif_receive_skb and returns the target
4367  * CPU from the RPS map of the receiving queue for a given skb.
4368  * rcu_read_lock must be held on entry.
4369  */
4370 static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
4371                        struct rps_dev_flow **rflowp)
4372 {
4373         const struct rps_sock_flow_table *sock_flow_table;
4374         struct netdev_rx_queue *rxqueue = dev->_rx;
4375         struct rps_dev_flow_table *flow_table;
4376         struct rps_map *map;
4377         int cpu = -1;
4378         u32 tcpu;
4379         u32 hash;
4380
4381         if (skb_rx_queue_recorded(skb)) {
4382                 u16 index = skb_get_rx_queue(skb);
4383
4384                 if (unlikely(index >= dev->real_num_rx_queues)) {
4385                         WARN_ONCE(dev->real_num_rx_queues > 1,
4386                                   "%s received packet on queue %u, but number "
4387                                   "of RX queues is %u\n",
4388                                   dev->name, index, dev->real_num_rx_queues);
4389                         goto done;
4390                 }
4391                 rxqueue += index;
4392         }
4393
4394         /* Avoid computing hash if RFS/RPS is not active for this rxqueue */
4395
4396         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4397         map = rcu_dereference(rxqueue->rps_map);
4398         if (!flow_table && !map)
4399                 goto done;
4400
4401         skb_reset_network_header(skb);
4402         hash = skb_get_hash(skb);
4403         if (!hash)
4404                 goto done;
4405
4406         sock_flow_table = rcu_dereference(rps_sock_flow_table);
4407         if (flow_table && sock_flow_table) {
4408                 struct rps_dev_flow *rflow;
4409                 u32 next_cpu;
4410                 u32 ident;
4411
4412                 /* First check into global flow table if there is a match */
4413                 ident = sock_flow_table->ents[hash & sock_flow_table->mask];
4414                 if ((ident ^ hash) & ~rps_cpu_mask)
4415                         goto try_rps;
4416
4417                 next_cpu = ident & rps_cpu_mask;
4418
4419                 /* OK, now we know there is a match,
4420                  * we can look at the local (per receive queue) flow table
4421                  */
4422                 rflow = &flow_table->flows[hash & flow_table->mask];
4423                 tcpu = rflow->cpu;
4424
4425                 /*
4426                  * If the desired CPU (where last recvmsg was done) is
4427                  * different from current CPU (one in the rx-queue flow
4428                  * table entry), switch if one of the following holds:
4429                  *   - Current CPU is unset (>= nr_cpu_ids).
4430                  *   - Current CPU is offline.
4431                  *   - The current CPU's queue tail has advanced beyond the
4432                  *     last packet that was enqueued using this table entry.
4433                  *     This guarantees that all previous packets for the flow
4434                  *     have been dequeued, thus preserving in order delivery.
4435                  */
4436                 if (unlikely(tcpu != next_cpu) &&
4437                     (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
4438                      ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
4439                       rflow->last_qtail)) >= 0)) {
4440                         tcpu = next_cpu;
4441                         rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
4442                 }
4443
4444                 if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
4445                         *rflowp = rflow;
4446                         cpu = tcpu;
4447                         goto done;
4448                 }
4449         }
4450
4451 try_rps:
4452
4453         if (map) {
4454                 tcpu = map->cpus[reciprocal_scale(hash, map->len)];
4455                 if (cpu_online(tcpu)) {
4456                         cpu = tcpu;
4457                         goto done;
4458                 }
4459         }
4460
4461 done:
4462         return cpu;
4463 }
4464
4465 #ifdef CONFIG_RFS_ACCEL
4466
4467 /**
4468  * rps_may_expire_flow - check whether an RFS hardware filter may be removed
4469  * @dev: Device on which the filter was set
4470  * @rxq_index: RX queue index
4471  * @flow_id: Flow ID passed to ndo_rx_flow_steer()
4472  * @filter_id: Filter ID returned by ndo_rx_flow_steer()
4473  *
4474  * Drivers that implement ndo_rx_flow_steer() should periodically call
4475  * this function for each installed filter and remove the filters for
4476  * which it returns %true.
4477  */
4478 bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
4479                          u32 flow_id, u16 filter_id)
4480 {
4481         struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
4482         struct rps_dev_flow_table *flow_table;
4483         struct rps_dev_flow *rflow;
4484         bool expire = true;
4485         unsigned int cpu;
4486
4487         rcu_read_lock();
4488         flow_table = rcu_dereference(rxqueue->rps_flow_table);
4489         if (flow_table && flow_id <= flow_table->mask) {
4490                 rflow = &flow_table->flows[flow_id];
4491                 cpu = READ_ONCE(rflow->cpu);
4492                 if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
4493                     ((int)(per_cpu(softnet_data, cpu).input_queue_head -
4494                            rflow->last_qtail) <
4495                      (int)(10 * flow_table->mask)))
4496                         expire = false;
4497         }
4498         rcu_read_unlock();
4499         return expire;
4500 }
4501 EXPORT_SYMBOL(rps_may_expire_flow);
4502
4503 #endif /* CONFIG_RFS_ACCEL */
4504
4505 /* Called from hardirq (IPI) context */
4506 static void rps_trigger_softirq(void *data)
4507 {
4508         struct softnet_data *sd = data;
4509
4510         ____napi_schedule(sd, &sd->backlog);
4511         sd->received_rps++;
4512 }
4513
4514 #endif /* CONFIG_RPS */
4515
4516 /*
4517  * Check if this softnet_data structure is another cpu one
4518  * If yes, queue it to our IPI list and return 1
4519  * If no, return 0
4520  */
4521 static int napi_schedule_rps(struct softnet_data *sd)
4522 {
4523         struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
4524
4525 #ifdef CONFIG_RPS
4526         if (sd != mysd) {
4527                 sd->rps_ipi_next = mysd->rps_ipi_list;
4528                 mysd->rps_ipi_list = sd;
4529
4530                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
4531                 return 1;
4532         }
4533 #endif /* CONFIG_RPS */
4534         __napi_schedule_irqoff(&mysd->backlog);
4535         return 0;
4536 }
4537
4538 #ifdef CONFIG_NET_FLOW_LIMIT
4539 int netdev_flow_limit_table_len __read_mostly = (1 << 12);
4540 #endif
4541
4542 static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
4543 {
4544 #ifdef CONFIG_NET_FLOW_LIMIT
4545         struct sd_flow_limit *fl;
4546         struct softnet_data *sd;
4547         unsigned int old_flow, new_flow;
4548
4549         if (qlen < (netdev_max_backlog >> 1))
4550                 return false;
4551
4552         sd = this_cpu_ptr(&softnet_data);
4553
4554         rcu_read_lock();
4555         fl = rcu_dereference(sd->flow_limit);
4556         if (fl) {
4557                 new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
4558                 old_flow = fl->history[fl->history_head];
4559                 fl->history[fl->history_head] = new_flow;
4560
4561                 fl->history_head++;
4562                 fl->history_head &= FLOW_LIMIT_HISTORY - 1;
4563
4564                 if (likely(fl->buckets[old_flow]))
4565                         fl->buckets[old_flow]--;
4566
4567                 if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
4568                         fl->count++;
4569                         rcu_read_unlock();
4570                         return true;
4571                 }
4572         }
4573         rcu_read_unlock();
4574 #endif
4575         return false;
4576 }
4577
4578 /*
4579  * enqueue_to_backlog is called to queue an skb to a per CPU backlog
4580  * queue (may be a remote CPU queue).
4581  */
4582 static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
4583                               unsigned int *qtail)
4584 {
4585         enum skb_drop_reason reason;
4586         struct softnet_data *sd;
4587         unsigned long flags;
4588         unsigned int qlen;
4589
4590         reason = SKB_DROP_REASON_NOT_SPECIFIED;
4591         sd = &per_cpu(softnet_data, cpu);
4592
4593         rps_lock_irqsave(sd, &flags);
4594         if (!netif_running(skb->dev))
4595                 goto drop;
4596         qlen = skb_queue_len(&sd->input_pkt_queue);
4597         if (qlen <= netdev_max_backlog && !skb_flow_limit(skb, qlen)) {
4598                 if (qlen) {
4599 enqueue:
4600                         __skb_queue_tail(&sd->input_pkt_queue, skb);
4601                         input_queue_tail_incr_save(sd, qtail);
4602                         rps_unlock_irq_restore(sd, &flags);
4603                         return NET_RX_SUCCESS;
4604                 }
4605
4606                 /* Schedule NAPI for backlog device
4607                  * We can use non atomic operation since we own the queue lock
4608                  */
4609                 if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
4610                         napi_schedule_rps(sd);
4611                 goto enqueue;
4612         }
4613         reason = SKB_DROP_REASON_CPU_BACKLOG;
4614
4615 drop:
4616         sd->dropped++;
4617         rps_unlock_irq_restore(sd, &flags);
4618
4619         dev_core_stats_rx_dropped_inc(skb->dev);
4620         kfree_skb_reason(skb, reason);
4621         return NET_RX_DROP;
4622 }
4623
4624 static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
4625 {
4626         struct net_device *dev = skb->dev;
4627         struct netdev_rx_queue *rxqueue;
4628
4629         rxqueue = dev->_rx;
4630
4631         if (skb_rx_queue_recorded(skb)) {
4632                 u16 index = skb_get_rx_queue(skb);
4633
4634                 if (unlikely(index >= dev->real_num_rx_queues)) {
4635                         WARN_ONCE(dev->real_num_rx_queues > 1,
4636                                   "%s received packet on queue %u, but number "
4637                                   "of RX queues is %u\n",
4638                                   dev->name, index, dev->real_num_rx_queues);
4639
4640                         return rxqueue; /* Return first rxqueue */
4641                 }
4642                 rxqueue += index;
4643         }
4644         return rxqueue;
4645 }
4646
4647 u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp,
4648                              struct bpf_prog *xdp_prog)
4649 {
4650         void *orig_data, *orig_data_end, *hard_start;
4651         struct netdev_rx_queue *rxqueue;
4652         bool orig_bcast, orig_host;
4653         u32 mac_len, frame_sz;
4654         __be16 orig_eth_type;
4655         struct ethhdr *eth;
4656         u32 metalen, act;
4657         int off;
4658
4659         /* The XDP program wants to see the packet starting at the MAC
4660          * header.
4661          */
4662         mac_len = skb->data - skb_mac_header(skb);
4663         hard_start = skb->data - skb_headroom(skb);
4664
4665         /* SKB "head" area always have tailroom for skb_shared_info */
4666         frame_sz = (void *)skb_end_pointer(skb) - hard_start;
4667         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
4668
4669         rxqueue = netif_get_rxqueue(skb);
4670         xdp_init_buff(xdp, frame_sz, &rxqueue->xdp_rxq);
4671         xdp_prepare_buff(xdp, hard_start, skb_headroom(skb) - mac_len,
4672                          skb_headlen(skb) + mac_len, true);
4673
4674         orig_data_end = xdp->data_end;
4675         orig_data = xdp->data;
4676         eth = (struct ethhdr *)xdp->data;
4677         orig_host = ether_addr_equal_64bits(eth->h_dest, skb->dev->dev_addr);
4678         orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
4679         orig_eth_type = eth->h_proto;
4680
4681         act = bpf_prog_run_xdp(xdp_prog, xdp);
4682
4683         /* check if bpf_xdp_adjust_head was used */
4684         off = xdp->data - orig_data;
4685         if (off) {
4686                 if (off > 0)
4687                         __skb_pull(skb, off);
4688                 else if (off < 0)
4689                         __skb_push(skb, -off);
4690
4691                 skb->mac_header += off;
4692                 skb_reset_network_header(skb);
4693         }
4694
4695         /* check if bpf_xdp_adjust_tail was used */
4696         off = xdp->data_end - orig_data_end;
4697         if (off != 0) {
4698                 skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
4699                 skb->len += off; /* positive on grow, negative on shrink */
4700         }
4701
4702         /* check if XDP changed eth hdr such SKB needs update */
4703         eth = (struct ethhdr *)xdp->data;
4704         if ((orig_eth_type != eth->h_proto) ||
4705             (orig_host != ether_addr_equal_64bits(eth->h_dest,
4706                                                   skb->dev->dev_addr)) ||
4707             (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
4708                 __skb_push(skb, ETH_HLEN);
4709                 skb->pkt_type = PACKET_HOST;
4710                 skb->protocol = eth_type_trans(skb, skb->dev);
4711         }
4712
4713         /* Redirect/Tx gives L2 packet, code that will reuse skb must __skb_pull
4714          * before calling us again on redirect path. We do not call do_redirect
4715          * as we leave that up to the caller.
4716          *
4717          * Caller is responsible for managing lifetime of skb (i.e. calling
4718          * kfree_skb in response to actions it cannot handle/XDP_DROP).
4719          */
4720         switch (act) {
4721         case XDP_REDIRECT:
4722         case XDP_TX:
4723                 __skb_push(skb, mac_len);
4724                 break;
4725         case XDP_PASS:
4726                 metalen = xdp->data - xdp->data_meta;
4727                 if (metalen)
4728                         skb_metadata_set(skb, metalen);
4729                 break;
4730         }
4731
4732         return act;
4733 }
4734
4735 static u32 netif_receive_generic_xdp(struct sk_buff *skb,
4736                                      struct xdp_buff *xdp,
4737                                      struct bpf_prog *xdp_prog)
4738 {
4739         u32 act = XDP_DROP;
4740
4741         /* Reinjected packets coming from act_mirred or similar should
4742          * not get XDP generic processing.
4743          */
4744         if (skb_is_redirected(skb))
4745                 return XDP_PASS;
4746
4747         /* XDP packets must be linear and must have sufficient headroom
4748          * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
4749          * native XDP provides, thus we need to do it here as well.
4750          */
4751         if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
4752             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
4753                 int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
4754                 int troom = skb->tail + skb->data_len - skb->end;
4755
4756                 /* In case we have to go down the path and also linearize,
4757                  * then lets do the pskb_expand_head() work just once here.
4758                  */
4759                 if (pskb_expand_head(skb,
4760                                      hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
4761                                      troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
4762                         goto do_drop;
4763                 if (skb_linearize(skb))
4764                         goto do_drop;
4765         }
4766
4767         act = bpf_prog_run_generic_xdp(skb, xdp, xdp_prog);
4768         switch (act) {
4769         case XDP_REDIRECT:
4770         case XDP_TX:
4771         case XDP_PASS:
4772                 break;
4773         default:
4774                 bpf_warn_invalid_xdp_action(skb->dev, xdp_prog, act);
4775                 fallthrough;
4776         case XDP_ABORTED:
4777                 trace_xdp_exception(skb->dev, xdp_prog, act);
4778                 fallthrough;
4779         case XDP_DROP:
4780         do_drop:
4781                 kfree_skb(skb);
4782                 break;
4783         }
4784
4785         return act;
4786 }
4787
4788 /* When doing generic XDP we have to bypass the qdisc layer and the
4789  * network taps in order to match in-driver-XDP behavior.
4790  */
4791 void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
4792 {
4793         struct net_device *dev = skb->dev;
4794         struct netdev_queue *txq;
4795         bool free_skb = true;
4796         int cpu, rc;
4797
4798         txq = netdev_core_pick_tx(dev, skb, NULL);
4799         cpu = smp_processor_id();
4800         HARD_TX_LOCK(dev, txq, cpu);
4801         if (!netif_xmit_stopped(txq)) {
4802                 rc = netdev_start_xmit(skb, dev, txq, 0);
4803                 if (dev_xmit_complete(rc))
4804                         free_skb = false;
4805         }
4806         HARD_TX_UNLOCK(dev, txq);
4807         if (free_skb) {
4808                 trace_xdp_exception(dev, xdp_prog, XDP_TX);
4809                 kfree_skb(skb);
4810         }
4811 }
4812
4813 static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
4814
4815 int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
4816 {
4817         if (xdp_prog) {
4818                 struct xdp_buff xdp;
4819                 u32 act;
4820                 int err;
4821
4822                 act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
4823                 if (act != XDP_PASS) {
4824                         switch (act) {
4825                         case XDP_REDIRECT:
4826                                 err = xdp_do_generic_redirect(skb->dev, skb,
4827                                                               &xdp, xdp_prog);
4828                                 if (err)
4829                                         goto out_redir;
4830                                 break;
4831                         case XDP_TX:
4832                                 generic_xdp_tx(skb, xdp_prog);
4833                                 break;
4834                         }
4835                         return XDP_DROP;
4836                 }
4837         }
4838         return XDP_PASS;
4839 out_redir:
4840         kfree_skb_reason(skb, SKB_DROP_REASON_XDP);
4841         return XDP_DROP;
4842 }
4843 EXPORT_SYMBOL_GPL(do_xdp_generic);
4844
4845 static int netif_rx_internal(struct sk_buff *skb)
4846 {
4847         int ret;
4848
4849         net_timestamp_check(netdev_tstamp_prequeue, skb);
4850
4851         trace_netif_rx(skb);
4852
4853 #ifdef CONFIG_RPS
4854         if (static_branch_unlikely(&rps_needed)) {
4855                 struct rps_dev_flow voidflow, *rflow = &voidflow;
4856                 int cpu;
4857
4858                 rcu_read_lock();
4859
4860                 cpu = get_rps_cpu(skb->dev, skb, &rflow);
4861                 if (cpu < 0)
4862                         cpu = smp_processor_id();
4863
4864                 ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
4865
4866                 rcu_read_unlock();
4867         } else
4868 #endif
4869         {
4870                 unsigned int qtail;
4871
4872                 ret = enqueue_to_backlog(skb, smp_processor_id(), &qtail);
4873         }
4874         return ret;
4875 }
4876
4877 /**
4878  *      __netif_rx      -       Slightly optimized version of netif_rx
4879  *      @skb: buffer to post
4880  *
4881  *      This behaves as netif_rx except that it does not disable bottom halves.
4882  *      As a result this function may only be invoked from the interrupt context
4883  *      (either hard or soft interrupt).
4884  */
4885 int __netif_rx(struct sk_buff *skb)
4886 {
4887         int ret;
4888
4889         lockdep_assert_once(hardirq_count() | softirq_count());
4890
4891         trace_netif_rx_entry(skb);
4892         ret = netif_rx_internal(skb);
4893         trace_netif_rx_exit(ret);
4894         return ret;
4895 }
4896 EXPORT_SYMBOL(__netif_rx);
4897
4898 /**
4899  *      netif_rx        -       post buffer to the network code
4900  *      @skb: buffer to post
4901  *
4902  *      This function receives a packet from a device driver and queues it for
4903  *      the upper (protocol) levels to process via the backlog NAPI device. It
4904  *      always succeeds. The buffer may be dropped during processing for
4905  *      congestion control or by the protocol layers.
4906  *      The network buffer is passed via the backlog NAPI device. Modern NIC
4907  *      driver should use NAPI and GRO.
4908  *      This function can used from interrupt and from process context. The
4909  *      caller from process context must not disable interrupts before invoking
4910  *      this function.
4911  *
4912  *      return values:
4913  *      NET_RX_SUCCESS  (no congestion)
4914  *      NET_RX_DROP     (packet was dropped)
4915  *
4916  */
4917 int netif_rx(struct sk_buff *skb)
4918 {
4919         bool need_bh_off = !(hardirq_count() | softirq_count());
4920         int ret;
4921
4922         if (need_bh_off)
4923                 local_bh_disable();
4924         trace_netif_rx_entry(skb);
4925         ret = netif_rx_internal(skb);
4926         trace_netif_rx_exit(ret);
4927         if (need_bh_off)
4928                 local_bh_enable();
4929         return ret;
4930 }
4931 EXPORT_SYMBOL(netif_rx);
4932
4933 static __latent_entropy void net_tx_action(struct softirq_action *h)
4934 {
4935         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
4936
4937         if (sd->completion_queue) {
4938                 struct sk_buff *clist;
4939
4940                 local_irq_disable();
4941                 clist = sd->completion_queue;
4942                 sd->completion_queue = NULL;
4943                 local_irq_enable();
4944
4945                 while (clist) {
4946                         struct sk_buff *skb = clist;
4947
4948                         clist = clist->next;
4949
4950                         WARN_ON(refcount_read(&skb->users));
4951                         if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
4952                                 trace_consume_skb(skb);
4953                         else
4954                                 trace_kfree_skb(skb, net_tx_action,
4955                                                 SKB_DROP_REASON_NOT_SPECIFIED);
4956
4957                         if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
4958                                 __kfree_skb(skb);
4959                         else
4960                                 __kfree_skb_defer(skb);
4961                 }
4962         }
4963
4964         if (sd->output_queue) {
4965                 struct Qdisc *head;
4966
4967                 local_irq_disable();
4968                 head = sd->output_queue;
4969                 sd->output_queue = NULL;
4970                 sd->output_queue_tailp = &sd->output_queue;
4971                 local_irq_enable();
4972
4973                 rcu_read_lock();
4974
4975                 while (head) {
4976                         struct Qdisc *q = head;
4977                         spinlock_t *root_lock = NULL;
4978
4979                         head = head->next_sched;
4980
4981                         /* We need to make sure head->next_sched is read
4982                          * before clearing __QDISC_STATE_SCHED
4983                          */
4984                         smp_mb__before_atomic();
4985
4986                         if (!(q->flags & TCQ_F_NOLOCK)) {
4987                                 root_lock = qdisc_lock(q);
4988                                 spin_lock(root_lock);
4989                         } else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
4990                                                      &q->state))) {
4991                                 /* There is a synchronize_net() between
4992                                  * STATE_DEACTIVATED flag being set and
4993                                  * qdisc_reset()/some_qdisc_is_busy() in
4994                                  * dev_deactivate(), so we can safely bail out
4995                                  * early here to avoid data race between
4996                                  * qdisc_deactivate() and some_qdisc_is_busy()
4997                                  * for lockless qdisc.
4998                                  */
4999                                 clear_bit(__QDISC_STATE_SCHED, &q->state);
5000                                 continue;
5001                         }
5002
5003                         clear_bit(__QDISC_STATE_SCHED, &q->state);
5004                         qdisc_run(q);
5005                         if (root_lock)
5006                                 spin_unlock(root_lock);
5007                 }
5008
5009                 rcu_read_unlock();
5010         }
5011
5012         xfrm_dev_backlog(sd);
5013 }
5014
5015 #if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
5016 /* This hook is defined here for ATM LANE */
5017 int (*br_fdb_test_addr_hook)(struct net_device *dev,
5018                              unsigned char *addr) __read_mostly;
5019 EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
5020 #endif
5021
5022 static inline struct sk_buff *
5023 sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
5024                    struct net_device *orig_dev, bool *another)
5025 {
5026 #ifdef CONFIG_NET_CLS_ACT
5027         struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
5028         struct tcf_result cl_res;
5029
5030         /* If there's at least one ingress present somewhere (so
5031          * we get here via enabled static key), remaining devices
5032          * that are not configured with an ingress qdisc will bail
5033          * out here.
5034          */
5035         if (!miniq)
5036                 return skb;
5037
5038         if (*pt_prev) {
5039                 *ret = deliver_skb(skb, *pt_prev, orig_dev);
5040                 *pt_prev = NULL;
5041         }
5042
5043         qdisc_skb_cb(skb)->pkt_len = skb->len;
5044         tc_skb_cb(skb)->mru = 0;
5045         tc_skb_cb(skb)->post_ct = false;
5046         skb->tc_at_ingress = 1;
5047         mini_qdisc_bstats_cpu_update(miniq, skb);
5048
5049         switch (tcf_classify(skb, miniq->block, miniq->filter_list, &cl_res, false)) {
5050         case TC_ACT_OK:
5051         case TC_ACT_RECLASSIFY:
5052                 skb->tc_index = TC_H_MIN(cl_res.classid);
5053                 break;
5054         case TC_ACT_SHOT:
5055                 mini_qdisc_qstats_cpu_drop(miniq);
5056                 kfree_skb_reason(skb, SKB_DROP_REASON_TC_INGRESS);
5057                 return NULL;
5058         case TC_ACT_STOLEN:
5059         case TC_ACT_QUEUED:
5060         case TC_ACT_TRAP:
5061                 consume_skb(skb);
5062                 return NULL;
5063         case TC_ACT_REDIRECT:
5064                 /* skb_mac_header check was done by cls/act_bpf, so
5065                  * we can safely push the L2 header back before
5066                  * redirecting to another netdev
5067                  */
5068                 __skb_push(skb, skb->mac_len);
5069                 if (skb_do_redirect(skb) == -EAGAIN) {
5070                         __skb_pull(skb, skb->mac_len);
5071                         *another = true;
5072                         break;
5073                 }
5074                 return NULL;
5075         case TC_ACT_CONSUMED:
5076                 return NULL;
5077         default:
5078                 break;
5079         }
5080 #endif /* CONFIG_NET_CLS_ACT */
5081         return skb;
5082 }
5083
5084 /**
5085  *      netdev_is_rx_handler_busy - check if receive handler is registered
5086  *      @dev: device to check
5087  *
5088  *      Check if a receive handler is already registered for a given device.
5089  *      Return true if there one.
5090  *
5091  *      The caller must hold the rtnl_mutex.
5092  */
5093 bool netdev_is_rx_handler_busy(struct net_device *dev)
5094 {
5095         ASSERT_RTNL();
5096         return dev && rtnl_dereference(dev->rx_handler);
5097 }
5098 EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
5099
5100 /**
5101  *      netdev_rx_handler_register - register receive handler
5102  *      @dev: device to register a handler for
5103  *      @rx_handler: receive handler to register
5104  *      @rx_handler_data: data pointer that is used by rx handler
5105  *
5106  *      Register a receive handler for a device. This handler will then be
5107  *      called from __netif_receive_skb. A negative errno code is returned
5108  *      on a failure.
5109  *
5110  *      The caller must hold the rtnl_mutex.
5111  *
5112  *      For a general description of rx_handler, see enum rx_handler_result.
5113  */
5114 int netdev_rx_handler_register(struct net_device *dev,
5115                                rx_handler_func_t *rx_handler,
5116                                void *rx_handler_data)
5117 {
5118         if (netdev_is_rx_handler_busy(dev))
5119                 return -EBUSY;
5120
5121         if (dev->priv_flags & IFF_NO_RX_HANDLER)
5122                 return -EINVAL;
5123
5124         /* Note: rx_handler_data must be set before rx_handler */
5125         rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
5126         rcu_assign_pointer(dev->rx_handler, rx_handler);
5127
5128         return 0;
5129 }
5130 EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
5131
5132 /**
5133  *      netdev_rx_handler_unregister - unregister receive handler
5134  *      @dev: device to unregister a handler from
5135  *
5136  *      Unregister a receive handler from a device.
5137  *
5138  *      The caller must hold the rtnl_mutex.
5139  */
5140 void netdev_rx_handler_unregister(struct net_device *dev)
5141 {
5142
5143         ASSERT_RTNL();
5144         RCU_INIT_POINTER(dev->rx_handler, NULL);
5145         /* a reader seeing a non NULL rx_handler in a rcu_read_lock()
5146          * section has a guarantee to see a non NULL rx_handler_data
5147          * as well.
5148          */
5149         synchronize_net();
5150         RCU_INIT_POINTER(dev->rx_handler_data, NULL);
5151 }
5152 EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
5153
5154 /*
5155  * Limit the use of PFMEMALLOC reserves to those protocols that implement
5156  * the special handling of PFMEMALLOC skbs.
5157  */
5158 static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
5159 {
5160         switch (skb->protocol) {
5161         case htons(ETH_P_ARP):
5162         case htons(ETH_P_IP):
5163         case htons(ETH_P_IPV6):
5164         case htons(ETH_P_8021Q):
5165         case htons(ETH_P_8021AD):
5166                 return true;
5167         default:
5168                 return false;
5169         }
5170 }
5171
5172 static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
5173                              int *ret, struct net_device *orig_dev)
5174 {
5175         if (nf_hook_ingress_active(skb)) {
5176                 int ingress_retval;
5177
5178                 if (*pt_prev) {
5179                         *ret = deliver_skb(skb, *pt_prev, orig_dev);
5180                         *pt_prev = NULL;
5181                 }
5182
5183                 rcu_read_lock();
5184                 ingress_retval = nf_hook_ingress(skb);
5185                 rcu_read_unlock();
5186                 return ingress_retval;
5187         }
5188         return 0;
5189 }
5190
5191 static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
5192                                     struct packet_type **ppt_prev)
5193 {
5194         struct packet_type *ptype, *pt_prev;
5195         rx_handler_func_t *rx_handler;
5196         struct sk_buff *skb = *pskb;
5197         struct net_device *orig_dev;
5198         bool deliver_exact = false;
5199         int ret = NET_RX_DROP;
5200         __be16 type;
5201
5202         net_timestamp_check(!netdev_tstamp_prequeue, skb);
5203
5204         trace_netif_receive_skb(skb);
5205
5206         orig_dev = skb->dev;
5207
5208         skb_reset_network_header(skb);
5209         if (!skb_transport_header_was_set(skb))
5210                 skb_reset_transport_header(skb);
5211         skb_reset_mac_len(skb);
5212
5213         pt_prev = NULL;
5214
5215 another_round:
5216         skb->skb_iif = skb->dev->ifindex;
5217
5218         __this_cpu_inc(softnet_data.processed);
5219
5220         if (static_branch_unlikely(&generic_xdp_needed_key)) {
5221                 int ret2;
5222
5223                 migrate_disable();
5224                 ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
5225                 migrate_enable();
5226
5227                 if (ret2 != XDP_PASS) {
5228                         ret = NET_RX_DROP;
5229                         goto out;
5230                 }
5231         }
5232
5233         if (eth_type_vlan(skb->protocol)) {
5234                 skb = skb_vlan_untag(skb);
5235                 if (unlikely(!skb))
5236                         goto out;
5237         }
5238
5239         if (skb_skip_tc_classify(skb))
5240                 goto skip_classify;
5241
5242         if (pfmemalloc)
5243                 goto skip_taps;
5244
5245         list_for_each_entry_rcu(ptype, &ptype_all, list) {
5246                 if (pt_prev)
5247                         ret = deliver_skb(skb, pt_prev, orig_dev);
5248                 pt_prev = ptype;
5249         }
5250
5251         list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
5252                 if (pt_prev)
5253                         ret = deliver_skb(skb, pt_prev, orig_dev);
5254                 pt_prev = ptype;
5255         }
5256
5257 skip_taps:
5258 #ifdef CONFIG_NET_INGRESS
5259         if (static_branch_unlikely(&ingress_needed_key)) {
5260                 bool another = false;
5261
5262                 nf_skip_egress(skb, true);
5263                 skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
5264                                          &another);
5265                 if (another)
5266                         goto another_round;
5267                 if (!skb)
5268                         goto out;
5269
5270                 nf_skip_egress(skb, false);
5271                 if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
5272                         goto out;
5273         }
5274 #endif
5275         skb_reset_redirect(skb);
5276 skip_classify:
5277         if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
5278                 goto drop;
5279
5280         if (skb_vlan_tag_present(skb)) {
5281                 if (pt_prev) {
5282                         ret = deliver_skb(skb, pt_prev, orig_dev);
5283                         pt_prev = NULL;
5284                 }
5285                 if (vlan_do_receive(&skb))
5286                         goto another_round;
5287                 else if (unlikely(!skb))
5288                         goto out;
5289         }
5290
5291         rx_handler = rcu_dereference(skb->dev->rx_handler);
5292         if (rx_handler) {
5293                 if (pt_prev) {
5294                         ret = deliver_skb(skb, pt_prev, orig_dev);
5295                         pt_prev = NULL;
5296                 }
5297                 switch (rx_handler(&skb)) {
5298                 case RX_HANDLER_CONSUMED:
5299                         ret = NET_RX_SUCCESS;
5300                         goto out;
5301                 case RX_HANDLER_ANOTHER:
5302                         goto another_round;
5303                 case RX_HANDLER_EXACT:
5304                         deliver_exact = true;
5305                         break;
5306                 case RX_HANDLER_PASS:
5307                         break;
5308                 default:
5309                         BUG();
5310                 }
5311         }
5312
5313         if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
5314 check_vlan_id:
5315                 if (skb_vlan_tag_get_id(skb)) {
5316                         /* Vlan id is non 0 and vlan_do_receive() above couldn't
5317                          * find vlan device.
5318                          */
5319                         skb->pkt_type = PACKET_OTHERHOST;
5320                 } else if (eth_type_vlan(skb->protocol)) {
5321                         /* Outer header is 802.1P with vlan 0, inner header is
5322                          * 802.1Q or 802.1AD and vlan_do_receive() above could
5323                          * not find vlan dev for vlan id 0.
5324                          */
5325                         __vlan_hwaccel_clear_tag(skb);
5326                         skb = skb_vlan_untag(skb);
5327                         if (unlikely(!skb))
5328                                 goto out;
5329                         if (vlan_do_receive(&skb))
5330                                 /* After stripping off 802.1P header with vlan 0
5331                                  * vlan dev is found for inner header.
5332                                  */
5333                                 goto another_round;
5334                         else if (unlikely(!skb))
5335                                 goto out;
5336                         else
5337                                 /* We have stripped outer 802.1P vlan 0 header.
5338                                  * But could not find vlan dev.
5339                                  * check again for vlan id to set OTHERHOST.
5340                                  */
5341                                 goto check_vlan_id;
5342                 }
5343                 /* Note: we might in the future use prio bits
5344                  * and set skb->priority like in vlan_do_receive()
5345                  * For the time being, just ignore Priority Code Point
5346                  */
5347                 __vlan_hwaccel_clear_tag(skb);
5348         }
5349
5350         type = skb->protocol;
5351
5352         /* deliver only exact match when indicated */
5353         if (likely(!deliver_exact)) {
5354                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5355                                        &ptype_base[ntohs(type) &
5356                                                    PTYPE_HASH_MASK]);
5357         }
5358
5359         deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5360                                &orig_dev->ptype_specific);
5361
5362         if (unlikely(skb->dev != orig_dev)) {
5363                 deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
5364                                        &skb->dev->ptype_specific);
5365         }
5366
5367         if (pt_prev) {
5368                 if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
5369                         goto drop;
5370                 *ppt_prev = pt_prev;
5371         } else {
5372 drop:
5373                 if (!deliver_exact) {
5374                         dev_core_stats_rx_dropped_inc(skb->dev);
5375                         kfree_skb_reason(skb, SKB_DROP_REASON_PTYPE_ABSENT);
5376                 } else {
5377                         dev_core_stats_rx_nohandler_inc(skb->dev);
5378                         kfree_skb(skb);
5379                 }
5380                 /* Jamal, now you will not able to escape explaining
5381                  * me how you were going to use this. :-)
5382                  */
5383                 ret = NET_RX_DROP;
5384         }
5385
5386 out:
5387         /* The invariant here is that if *ppt_prev is not NULL
5388          * then skb should also be non-NULL.
5389          *
5390          * Apparently *ppt_prev assignment above holds this invariant due to
5391          * skb dereferencing near it.
5392          */
5393         *pskb = skb;
5394         return ret;
5395 }
5396
5397 static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
5398 {
5399         struct net_device *orig_dev = skb->dev;
5400         struct packet_type *pt_prev = NULL;
5401         int ret;
5402
5403         ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5404         if (pt_prev)
5405                 ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
5406                                          skb->dev, pt_prev, orig_dev);
5407         return ret;
5408 }
5409
5410 /**
5411  *      netif_receive_skb_core - special purpose version of netif_receive_skb
5412  *      @skb: buffer to process
5413  *
5414  *      More direct receive version of netif_receive_skb().  It should
5415  *      only be used by callers that have a need to skip RPS and Generic XDP.
5416  *      Caller must also take care of handling if ``(page_is_)pfmemalloc``.
5417  *
5418  *      This function may only be called from softirq context and interrupts
5419  *      should be enabled.
5420  *
5421  *      Return values (usually ignored):
5422  *      NET_RX_SUCCESS: no congestion
5423  *      NET_RX_DROP: packet was dropped
5424  */
5425 int netif_receive_skb_core(struct sk_buff *skb)
5426 {
5427         int ret;
5428
5429         rcu_read_lock();
5430         ret = __netif_receive_skb_one_core(skb, false);
5431         rcu_read_unlock();
5432
5433         return ret;
5434 }
5435 EXPORT_SYMBOL(netif_receive_skb_core);
5436
5437 static inline void __netif_receive_skb_list_ptype(struct list_head *head,
5438                                                   struct packet_type *pt_prev,
5439                                                   struct net_device *orig_dev)
5440 {
5441         struct sk_buff *skb, *next;
5442
5443         if (!pt_prev)
5444                 return;
5445         if (list_empty(head))
5446                 return;
5447         if (pt_prev->list_func != NULL)
5448                 INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
5449                                    ip_list_rcv, head, pt_prev, orig_dev);
5450         else
5451                 list_for_each_entry_safe(skb, next, head, list) {
5452                         skb_list_del_init(skb);
5453                         pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
5454                 }
5455 }
5456
5457 static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
5458 {
5459         /* Fast-path assumptions:
5460          * - There is no RX handler.
5461          * - Only one packet_type matches.
5462          * If either of these fails, we will end up doing some per-packet
5463          * processing in-line, then handling the 'last ptype' for the whole
5464          * sublist.  This can't cause out-of-order delivery to any single ptype,
5465          * because the 'last ptype' must be constant across the sublist, and all
5466          * other ptypes are handled per-packet.
5467          */
5468         /* Current (common) ptype of sublist */
5469         struct packet_type *pt_curr = NULL;
5470         /* Current (common) orig_dev of sublist */
5471         struct net_device *od_curr = NULL;
5472         struct list_head sublist;
5473         struct sk_buff *skb, *next;
5474
5475         INIT_LIST_HEAD(&sublist);
5476         list_for_each_entry_safe(skb, next, head, list) {
5477                 struct net_device *orig_dev = skb->dev;
5478                 struct packet_type *pt_prev = NULL;
5479
5480                 skb_list_del_init(skb);
5481                 __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
5482                 if (!pt_prev)
5483                         continue;
5484                 if (pt_curr != pt_prev || od_curr != orig_dev) {
5485                         /* dispatch old sublist */
5486                         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5487                         /* start new sublist */
5488                         INIT_LIST_HEAD(&sublist);
5489                         pt_curr = pt_prev;
5490                         od_curr = orig_dev;
5491                 }
5492                 list_add_tail(&skb->list, &sublist);
5493         }
5494
5495         /* dispatch final sublist */
5496         __netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
5497 }
5498
5499 static int __netif_receive_skb(struct sk_buff *skb)
5500 {
5501         int ret;
5502
5503         if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
5504                 unsigned int noreclaim_flag;
5505
5506                 /*
5507                  * PFMEMALLOC skbs are special, they should
5508                  * - be delivered to SOCK_MEMALLOC sockets only
5509                  * - stay away from userspace
5510                  * - have bounded memory usage
5511                  *
5512                  * Use PF_MEMALLOC as this saves us from propagating the allocation
5513                  * context down to all allocation sites.
5514                  */
5515                 noreclaim_flag = memalloc_noreclaim_save();
5516                 ret = __netif_receive_skb_one_core(skb, true);
5517                 memalloc_noreclaim_restore(noreclaim_flag);
5518         } else
5519                 ret = __netif_receive_skb_one_core(skb, false);
5520
5521         return ret;
5522 }
5523
5524 static void __netif_receive_skb_list(struct list_head *head)
5525 {
5526         unsigned long noreclaim_flag = 0;
5527         struct sk_buff *skb, *next;
5528         bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
5529
5530         list_for_each_entry_safe(skb, next, head, list) {
5531                 if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
5532                         struct list_head sublist;
5533
5534                         /* Handle the previous sublist */
5535                         list_cut_before(&sublist, head, &skb->list);
5536                         if (!list_empty(&sublist))
5537                                 __netif_receive_skb_list_core(&sublist, pfmemalloc);
5538                         pfmemalloc = !pfmemalloc;
5539                         /* See comments in __netif_receive_skb */
5540                         if (pfmemalloc)
5541                                 noreclaim_flag = memalloc_noreclaim_save();
5542                         else
5543                                 memalloc_noreclaim_restore(noreclaim_flag);
5544                 }
5545         }
5546         /* Handle the remaining sublist */
5547         if (!list_empty(head))
5548                 __netif_receive_skb_list_core(head, pfmemalloc);
5549         /* Restore pflags */
5550         if (pfmemalloc)
5551                 memalloc_noreclaim_restore(noreclaim_flag);
5552 }
5553
5554 static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
5555 {
5556         struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
5557         struct bpf_prog *new = xdp->prog;
5558         int ret = 0;
5559
5560         switch (xdp->command) {
5561         case XDP_SETUP_PROG:
5562                 rcu_assign_pointer(dev->xdp_prog, new);
5563                 if (old)
5564                         bpf_prog_put(old);
5565
5566                 if (old && !new) {
5567                         static_branch_dec(&generic_xdp_needed_key);
5568                 } else if (new && !old) {
5569                         static_branch_inc(&generic_xdp_needed_key);
5570                         dev_disable_lro(dev);
5571                         dev_disable_gro_hw(dev);
5572                 }
5573                 break;
5574
5575         default:
5576                 ret = -EINVAL;
5577                 break;
5578         }
5579
5580         return ret;
5581 }
5582
5583 static int netif_receive_skb_internal(struct sk_buff *skb)
5584 {
5585         int ret;
5586
5587         net_timestamp_check(netdev_tstamp_prequeue, skb);
5588
5589         if (skb_defer_rx_timestamp(skb))
5590                 return NET_RX_SUCCESS;
5591
5592         rcu_read_lock();
5593 #ifdef CONFIG_RPS
5594         if (static_branch_unlikely(&rps_needed)) {
5595                 struct rps_dev_flow voidflow, *rflow = &voidflow;
5596                 int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5597
5598                 if (cpu >= 0) {
5599                         ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5600                         rcu_read_unlock();
5601                         return ret;
5602                 }
5603         }
5604 #endif
5605         ret = __netif_receive_skb(skb);
5606         rcu_read_unlock();
5607         return ret;
5608 }
5609
5610 void netif_receive_skb_list_internal(struct list_head *head)
5611 {
5612         struct sk_buff *skb, *next;
5613         struct list_head sublist;
5614
5615         INIT_LIST_HEAD(&sublist);
5616         list_for_each_entry_safe(skb, next, head, list) {
5617                 net_timestamp_check(netdev_tstamp_prequeue, skb);
5618                 skb_list_del_init(skb);
5619                 if (!skb_defer_rx_timestamp(skb))
5620                         list_add_tail(&skb->list, &sublist);
5621         }
5622         list_splice_init(&sublist, head);
5623
5624         rcu_read_lock();
5625 #ifdef CONFIG_RPS
5626         if (static_branch_unlikely(&rps_needed)) {
5627                 list_for_each_entry_safe(skb, next, head, list) {
5628                         struct rps_dev_flow voidflow, *rflow = &voidflow;
5629                         int cpu = get_rps_cpu(skb->dev, skb, &rflow);
5630
5631                         if (cpu >= 0) {
5632                                 /* Will be handled, remove from list */
5633                                 skb_list_del_init(skb);
5634                                 enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
5635                         }
5636                 }
5637         }
5638 #endif
5639         __netif_receive_skb_list(head);
5640         rcu_read_unlock();
5641 }
5642
5643 /**
5644  *      netif_receive_skb - process receive buffer from network
5645  *      @skb: buffer to process
5646  *
5647  *      netif_receive_skb() is the main receive data processing function.
5648  *      It always succeeds. The buffer may be dropped during processing
5649  *      for congestion control or by the protocol layers.
5650  *
5651  *      This function may only be called from softirq context and interrupts
5652  *      should be enabled.
5653  *
5654  *      Return values (usually ignored):
5655  *      NET_RX_SUCCESS: no congestion
5656  *      NET_RX_DROP: packet was dropped
5657  */
5658 int netif_receive_skb(struct sk_buff *skb)
5659 {
5660         int ret;
5661
5662         trace_netif_receive_skb_entry(skb);
5663
5664         ret = netif_receive_skb_internal(skb);
5665         trace_netif_receive_skb_exit(ret);
5666
5667         return ret;
5668 }
5669 EXPORT_SYMBOL(netif_receive_skb);
5670
5671 /**
5672  *      netif_receive_skb_list - process many receive buffers from network
5673  *      @head: list of skbs to process.
5674  *
5675  *      Since return value of netif_receive_skb() is normally ignored, and
5676  *      wouldn't be meaningful for a list, this function returns void.
5677  *
5678  *      This function may only be called from softirq context and interrupts
5679  *      should be enabled.
5680  */
5681 void netif_receive_skb_list(struct list_head *head)
5682 {
5683         struct sk_buff *skb;
5684
5685         if (list_empty(head))
5686                 return;
5687         if (trace_netif_receive_skb_list_entry_enabled()) {
5688                 list_for_each_entry(skb, head, list)
5689                         trace_netif_receive_skb_list_entry(skb);
5690         }
5691         netif_receive_skb_list_internal(head);
5692         trace_netif_receive_skb_list_exit(0);
5693 }
5694 EXPORT_SYMBOL(netif_receive_skb_list);
5695
5696 static DEFINE_PER_CPU(struct work_struct, flush_works);
5697
5698 /* Network device is going away, flush any packets still pending */
5699 static void flush_backlog(struct work_struct *work)
5700 {
5701         struct sk_buff *skb, *tmp;
5702         struct softnet_data *sd;
5703
5704         local_bh_disable();
5705         sd = this_cpu_ptr(&softnet_data);
5706
5707         rps_lock_irq_disable(sd);
5708         skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
5709                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5710                         __skb_unlink(skb, &sd->input_pkt_queue);
5711                         dev_kfree_skb_irq(skb);
5712                         input_queue_head_incr(sd);
5713                 }
5714         }
5715         rps_unlock_irq_enable(sd);
5716
5717         skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
5718                 if (skb->dev->reg_state == NETREG_UNREGISTERING) {
5719                         __skb_unlink(skb, &sd->process_queue);
5720                         kfree_skb(skb);
5721                         input_queue_head_incr(sd);
5722                 }
5723         }
5724         local_bh_enable();
5725 }
5726
5727 static bool flush_required(int cpu)
5728 {
5729 #if IS_ENABLED(CONFIG_RPS)
5730         struct softnet_data *sd = &per_cpu(softnet_data, cpu);
5731         bool do_flush;
5732
5733         rps_lock_irq_disable(sd);
5734
5735         /* as insertion into process_queue happens with the rps lock held,
5736          * process_queue access may race only with dequeue
5737          */
5738         do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
5739                    !skb_queue_empty_lockless(&sd->process_queue);
5740         rps_unlock_irq_enable(sd);
5741
5742         return do_flush;
5743 #endif
5744         /* without RPS we can't safely check input_pkt_queue: during a
5745          * concurrent remote skb_queue_splice() we can detect as empty both
5746          * input_pkt_queue and process_queue even if the latter could end-up
5747          * containing a lot of packets.
5748          */
5749         return true;
5750 }
5751
5752 static void flush_all_backlogs(void)
5753 {
5754         static cpumask_t flush_cpus;
5755         unsigned int cpu;
5756
5757         /* since we are under rtnl lock protection we can use static data
5758          * for the cpumask and avoid allocating on stack the possibly
5759          * large mask
5760          */
5761         ASSERT_RTNL();
5762
5763         cpus_read_lock();
5764
5765         cpumask_clear(&flush_cpus);
5766         for_each_online_cpu(cpu) {
5767                 if (flush_required(cpu)) {
5768                         queue_work_on(cpu, system_highpri_wq,
5769                                       per_cpu_ptr(&flush_works, cpu));
5770                         cpumask_set_cpu(cpu, &flush_cpus);
5771                 }
5772         }
5773
5774         /* we can have in flight packet[s] on the cpus we are not flushing,
5775          * synchronize_net() in unregister_netdevice_many() will take care of
5776          * them
5777          */
5778         for_each_cpu(cpu, &flush_cpus)
5779                 flush_work(per_cpu_ptr(&flush_works, cpu));
5780
5781         cpus_read_unlock();
5782 }
5783
5784 static void net_rps_send_ipi(struct softnet_data *remsd)
5785 {
5786 #ifdef CONFIG_RPS
5787         while (remsd) {
5788                 struct softnet_data *next = remsd->rps_ipi_next;
5789
5790                 if (cpu_online(remsd->cpu))
5791                         smp_call_function_single_async(remsd->cpu, &remsd->csd);
5792                 remsd = next;
5793         }
5794 #endif
5795 }
5796
5797 /*
5798  * net_rps_action_and_irq_enable sends any pending IPI's for rps.
5799  * Note: called with local irq disabled, but exits with local irq enabled.
5800  */
5801 static void net_rps_action_and_irq_enable(struct softnet_data *sd)
5802 {
5803 #ifdef CONFIG_RPS
5804         struct softnet_data *remsd = sd->rps_ipi_list;
5805
5806         if (remsd) {
5807                 sd->rps_ipi_list = NULL;
5808
5809                 local_irq_enable();
5810
5811                 /* Send pending IPI's to kick RPS processing on remote cpus. */
5812                 net_rps_send_ipi(remsd);
5813         } else
5814 #endif
5815                 local_irq_enable();
5816 }
5817
5818 static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
5819 {
5820 #ifdef CONFIG_RPS
5821         return sd->rps_ipi_list != NULL;
5822 #else
5823         return false;
5824 #endif
5825 }
5826
5827 static int process_backlog(struct napi_struct *napi, int quota)
5828 {
5829         struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
5830         bool again = true;
5831         int work = 0;
5832
5833         /* Check if we have pending ipi, its better to send them now,
5834          * not waiting net_rx_action() end.
5835          */
5836         if (sd_has_rps_ipi_waiting(sd)) {
5837                 local_irq_disable();
5838                 net_rps_action_and_irq_enable(sd);
5839         }
5840
5841         napi->weight = dev_rx_weight;
5842         while (again) {
5843                 struct sk_buff *skb;
5844
5845                 while ((skb = __skb_dequeue(&sd->process_queue))) {
5846                         rcu_read_lock();
5847                         __netif_receive_skb(skb);
5848                         rcu_read_unlock();
5849                         input_queue_head_incr(sd);
5850                         if (++work >= quota)
5851                                 return work;
5852
5853                 }
5854
5855                 rps_lock_irq_disable(sd);
5856                 if (skb_queue_empty(&sd->input_pkt_queue)) {
5857                         /*
5858                          * Inline a custom version of __napi_complete().
5859                          * only current cpu owns and manipulates this napi,
5860                          * and NAPI_STATE_SCHED is the only possible flag set
5861                          * on backlog.
5862                          * We can use a plain write instead of clear_bit(),
5863                          * and we dont need an smp_mb() memory barrier.
5864                          */
5865                         napi->state = 0;
5866                         again = false;
5867                 } else {
5868                         skb_queue_splice_tail_init(&sd->input_pkt_queue,
5869                                                    &sd->process_queue);
5870                 }
5871                 rps_unlock_irq_enable(sd);
5872         }
5873
5874         return work;
5875 }
5876
5877 /**
5878  * __napi_schedule - schedule for receive
5879  * @n: entry to schedule
5880  *
5881  * The entry's receive function will be scheduled to run.
5882  * Consider using __napi_schedule_irqoff() if hard irqs are masked.
5883  */
5884 void __napi_schedule(struct napi_struct *n)
5885 {
5886         unsigned long flags;
5887
5888         local_irq_save(flags);
5889         ____napi_schedule(this_cpu_ptr(&softnet_data), n);
5890         local_irq_restore(flags);
5891 }
5892 EXPORT_SYMBOL(__napi_schedule);
5893
5894 /**
5895  *      napi_schedule_prep - check if napi can be scheduled
5896  *      @n: napi context
5897  *
5898  * Test if NAPI routine is already running, and if not mark
5899  * it as running.  This is used as a condition variable to
5900  * insure only one NAPI poll instance runs.  We also make
5901  * sure there is no pending NAPI disable.
5902  */
5903 bool napi_schedule_prep(struct napi_struct *n)
5904 {
5905         unsigned long val, new;
5906
5907         do {
5908                 val = READ_ONCE(n->state);
5909                 if (unlikely(val & NAPIF_STATE_DISABLE))
5910                         return false;
5911                 new = val | NAPIF_STATE_SCHED;
5912
5913                 /* Sets STATE_MISSED bit if STATE_SCHED was already set
5914                  * This was suggested by Alexander Duyck, as compiler
5915                  * emits better code than :
5916                  * if (val & NAPIF_STATE_SCHED)
5917                  *     new |= NAPIF_STATE_MISSED;
5918                  */
5919                 new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
5920                                                    NAPIF_STATE_MISSED;
5921         } while (cmpxchg(&n->state, val, new) != val);
5922
5923         return !(val & NAPIF_STATE_SCHED);
5924 }
5925 EXPORT_SYMBOL(napi_schedule_prep);
5926
5927 /**
5928  * __napi_schedule_irqoff - schedule for receive
5929  * @n: entry to schedule
5930  *
5931  * Variant of __napi_schedule() assuming hard irqs are masked.
5932  *
5933  * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
5934  * because the interrupt disabled assumption might not be true
5935  * due to force-threaded interrupts and spinlock substitution.
5936  */
5937 void __napi_schedule_irqoff(struct napi_struct *n)
5938 {
5939         if (!IS_ENABLED(CONFIG_PREEMPT_RT))
5940                 ____napi_schedule(this_cpu_ptr(&softnet_data), n);
5941         else
5942                 __napi_schedule(n);
5943 }
5944 EXPORT_SYMBOL(__napi_schedule_irqoff);
5945
5946 bool napi_complete_done(struct napi_struct *n, int work_done)
5947 {
5948         unsigned long flags, val, new, timeout = 0;
5949         bool ret = true;
5950
5951         /*
5952          * 1) Don't let napi dequeue from the cpu poll list
5953          *    just in case its running on a different cpu.
5954          * 2) If we are busy polling, do nothing here, we have
5955          *    the guarantee we will be called later.
5956          */
5957         if (unlikely(n->state & (NAPIF_STATE_NPSVC |
5958                                  NAPIF_STATE_IN_BUSY_POLL)))
5959                 return false;
5960
5961         if (work_done) {
5962                 if (n->gro_bitmask)
5963                         timeout = READ_ONCE(n->dev->gro_flush_timeout);
5964                 n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
5965         }
5966         if (n->defer_hard_irqs_count > 0) {
5967                 n->defer_hard_irqs_count--;
5968                 timeout = READ_ONCE(n->dev->gro_flush_timeout);
5969                 if (timeout)
5970                         ret = false;
5971         }
5972         if (n->gro_bitmask) {
5973                 /* When the NAPI instance uses a timeout and keeps postponing
5974                  * it, we need to bound somehow the time packets are kept in
5975                  * the GRO layer
5976                  */
5977                 napi_gro_flush(n, !!timeout);
5978         }
5979
5980         gro_normal_list(n);
5981
5982         if (unlikely(!list_empty(&n->poll_list))) {
5983                 /* If n->poll_list is not empty, we need to mask irqs */
5984                 local_irq_save(flags);
5985                 list_del_init(&n->poll_list);
5986                 local_irq_restore(flags);
5987         }
5988
5989         do {
5990                 val = READ_ONCE(n->state);
5991
5992                 WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
5993
5994                 new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED |
5995                               NAPIF_STATE_SCHED_THREADED |
5996                               NAPIF_STATE_PREFER_BUSY_POLL);
5997
5998                 /* If STATE_MISSED was set, leave STATE_SCHED set,
5999                  * because we will call napi->poll() one more time.
6000                  * This C code was suggested by Alexander Duyck to help gcc.
6001                  */
6002                 new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
6003                                                     NAPIF_STATE_SCHED;
6004         } while (cmpxchg(&n->state, val, new) != val);
6005
6006         if (unlikely(val & NAPIF_STATE_MISSED)) {
6007                 __napi_schedule(n);
6008                 return false;
6009         }
6010
6011         if (timeout)
6012                 hrtimer_start(&n->timer, ns_to_ktime(timeout),
6013                               HRTIMER_MODE_REL_PINNED);
6014         return ret;
6015 }
6016 EXPORT_SYMBOL(napi_complete_done);
6017
6018 /* must be called under rcu_read_lock(), as we dont take a reference */
6019 static struct napi_struct *napi_by_id(unsigned int napi_id)
6020 {
6021         unsigned int hash = napi_id % HASH_SIZE(napi_hash);
6022         struct napi_struct *napi;
6023
6024         hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
6025                 if (napi->napi_id == napi_id)
6026                         return napi;
6027
6028         return NULL;
6029 }
6030
6031 #if defined(CONFIG_NET_RX_BUSY_POLL)
6032
6033 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
6034 {
6035         if (!skip_schedule) {
6036                 gro_normal_list(napi);
6037                 __napi_schedule(napi);
6038                 return;
6039         }
6040
6041         if (napi->gro_bitmask) {
6042                 /* flush too old packets
6043                  * If HZ < 1000, flush all packets.
6044                  */
6045                 napi_gro_flush(napi, HZ >= 1000);
6046         }
6047
6048         gro_normal_list(napi);
6049         clear_bit(NAPI_STATE_SCHED, &napi->state);
6050 }
6051
6052 static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock, bool prefer_busy_poll,
6053                            u16 budget)
6054 {
6055         bool skip_schedule = false;
6056         unsigned long timeout;
6057         int rc;
6058
6059         /* Busy polling means there is a high chance device driver hard irq
6060          * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
6061          * set in napi_schedule_prep().
6062          * Since we are about to call napi->poll() once more, we can safely
6063          * clear NAPI_STATE_MISSED.
6064          *
6065          * Note: x86 could use a single "lock and ..." instruction
6066          * to perform these two clear_bit()
6067          */
6068         clear_bit(NAPI_STATE_MISSED, &napi->state);
6069         clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
6070
6071         local_bh_disable();
6072
6073         if (prefer_busy_poll) {
6074                 napi->defer_hard_irqs_count = READ_ONCE(napi->dev->napi_defer_hard_irqs);
6075                 timeout = READ_ONCE(napi->dev->gro_flush_timeout);
6076                 if (napi->defer_hard_irqs_count && timeout) {
6077                         hrtimer_start(&napi->timer, ns_to_ktime(timeout), HRTIMER_MODE_REL_PINNED);
6078                         skip_schedule = true;
6079                 }
6080         }
6081
6082         /* All we really want here is to re-enable device interrupts.
6083          * Ideally, a new ndo_busy_poll_stop() could avoid another round.
6084          */
6085         rc = napi->poll(napi, budget);
6086         /* We can't gro_normal_list() here, because napi->poll() might have
6087          * rearmed the napi (napi_complete_done()) in which case it could
6088          * already be running on another CPU.
6089          */
6090         trace_napi_poll(napi, rc, budget);
6091         netpoll_poll_unlock(have_poll_lock);
6092         if (rc == budget)
6093                 __busy_poll_stop(napi, skip_schedule);
6094         local_bh_enable();
6095 }
6096
6097 void napi_busy_loop(unsigned int napi_id,
6098                     bool (*loop_end)(void *, unsigned long),
6099                     void *loop_end_arg, bool prefer_busy_poll, u16 budget)
6100 {
6101         unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
6102         int (*napi_poll)(struct napi_struct *napi, int budget);
6103         void *have_poll_lock = NULL;
6104         struct napi_struct *napi;
6105
6106 restart:
6107         napi_poll = NULL;
6108
6109         rcu_read_lock();
6110
6111         napi = napi_by_id(napi_id);
6112         if (!napi)
6113                 goto out;
6114
6115         preempt_disable();
6116         for (;;) {
6117                 int work = 0;
6118
6119                 local_bh_disable();
6120                 if (!napi_poll) {
6121                         unsigned long val = READ_ONCE(napi->state);
6122
6123                         /* If multiple threads are competing for this napi,
6124                          * we avoid dirtying napi->state as much as we can.
6125                          */
6126                         if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
6127                                    NAPIF_STATE_IN_BUSY_POLL)) {
6128                                 if (prefer_busy_poll)
6129                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6130                                 goto count;
6131                         }
6132                         if (cmpxchg(&napi->state, val,
6133                                     val | NAPIF_STATE_IN_BUSY_POLL |
6134                                           NAPIF_STATE_SCHED) != val) {
6135                                 if (prefer_busy_poll)
6136                                         set_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6137                                 goto count;
6138                         }
6139                         have_poll_lock = netpoll_poll_lock(napi);
6140                         napi_poll = napi->poll;
6141                 }
6142                 work = napi_poll(napi, budget);
6143                 trace_napi_poll(napi, work, budget);
6144                 gro_normal_list(napi);
6145 count:
6146                 if (work > 0)
6147                         __NET_ADD_STATS(dev_net(napi->dev),
6148                                         LINUX_MIB_BUSYPOLLRXPACKETS, work);
6149                 local_bh_enable();
6150
6151                 if (!loop_end || loop_end(loop_end_arg, start_time))
6152                         break;
6153
6154                 if (unlikely(need_resched())) {
6155                         if (napi_poll)
6156                                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6157                         preempt_enable();
6158                         rcu_read_unlock();
6159                         cond_resched();
6160                         if (loop_end(loop_end_arg, start_time))
6161                                 return;
6162                         goto restart;
6163                 }
6164                 cpu_relax();
6165         }
6166         if (napi_poll)
6167                 busy_poll_stop(napi, have_poll_lock, prefer_busy_poll, budget);
6168         preempt_enable();
6169 out:
6170         rcu_read_unlock();
6171 }
6172 EXPORT_SYMBOL(napi_busy_loop);
6173
6174 #endif /* CONFIG_NET_RX_BUSY_POLL */
6175
6176 static void napi_hash_add(struct napi_struct *napi)
6177 {
6178         if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
6179                 return;
6180
6181         spin_lock(&napi_hash_lock);
6182
6183         /* 0..NR_CPUS range is reserved for sender_cpu use */
6184         do {
6185                 if (unlikely(++napi_gen_id < MIN_NAPI_ID))
6186                         napi_gen_id = MIN_NAPI_ID;
6187         } while (napi_by_id(napi_gen_id));
6188         napi->napi_id = napi_gen_id;
6189
6190         hlist_add_head_rcu(&napi->napi_hash_node,
6191                            &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
6192
6193         spin_unlock(&napi_hash_lock);
6194 }
6195
6196 /* Warning : caller is responsible to make sure rcu grace period
6197  * is respected before freeing memory containing @napi
6198  */
6199 static void napi_hash_del(struct napi_struct *napi)
6200 {
6201         spin_lock(&napi_hash_lock);
6202
6203         hlist_del_init_rcu(&napi->napi_hash_node);
6204
6205         spin_unlock(&napi_hash_lock);
6206 }
6207
6208 static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
6209 {
6210         struct napi_struct *napi;
6211
6212         napi = container_of(timer, struct napi_struct, timer);
6213
6214         /* Note : we use a relaxed variant of napi_schedule_prep() not setting
6215          * NAPI_STATE_MISSED, since we do not react to a device IRQ.
6216          */
6217         if (!napi_disable_pending(napi) &&
6218             !test_and_set_bit(NAPI_STATE_SCHED, &napi->state)) {
6219                 clear_bit(NAPI_STATE_PREFER_BUSY_POLL, &napi->state);
6220                 __napi_schedule_irqoff(napi);
6221         }
6222
6223         return HRTIMER_NORESTART;
6224 }
6225
6226 static void init_gro_hash(struct napi_struct *napi)
6227 {
6228         int i;
6229
6230         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6231                 INIT_LIST_HEAD(&napi->gro_hash[i].list);
6232                 napi->gro_hash[i].count = 0;
6233         }
6234         napi->gro_bitmask = 0;
6235 }
6236
6237 int dev_set_threaded(struct net_device *dev, bool threaded)
6238 {
6239         struct napi_struct *napi;
6240         int err = 0;
6241
6242         if (dev->threaded == threaded)
6243                 return 0;
6244
6245         if (threaded) {
6246                 list_for_each_entry(napi, &dev->napi_list, dev_list) {
6247                         if (!napi->thread) {
6248                                 err = napi_kthread_create(napi);
6249                                 if (err) {
6250                                         threaded = false;
6251                                         break;
6252                                 }
6253                         }
6254                 }
6255         }
6256
6257         dev->threaded = threaded;
6258
6259         /* Make sure kthread is created before THREADED bit
6260          * is set.
6261          */
6262         smp_mb__before_atomic();
6263
6264         /* Setting/unsetting threaded mode on a napi might not immediately
6265          * take effect, if the current napi instance is actively being
6266          * polled. In this case, the switch between threaded mode and
6267          * softirq mode will happen in the next round of napi_schedule().
6268          * This should not cause hiccups/stalls to the live traffic.
6269          */
6270         list_for_each_entry(napi, &dev->napi_list, dev_list) {
6271                 if (threaded)
6272                         set_bit(NAPI_STATE_THREADED, &napi->state);
6273                 else
6274                         clear_bit(NAPI_STATE_THREADED, &napi->state);
6275         }
6276
6277         return err;
6278 }
6279 EXPORT_SYMBOL(dev_set_threaded);
6280
6281 void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
6282                     int (*poll)(struct napi_struct *, int), int weight)
6283 {
6284         if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
6285                 return;
6286
6287         INIT_LIST_HEAD(&napi->poll_list);
6288         INIT_HLIST_NODE(&napi->napi_hash_node);
6289         hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
6290         napi->timer.function = napi_watchdog;
6291         init_gro_hash(napi);
6292         napi->skb = NULL;
6293         INIT_LIST_HEAD(&napi->rx_list);
6294         napi->rx_count = 0;
6295         napi->poll = poll;
6296         if (weight > NAPI_POLL_WEIGHT)
6297                 netdev_err_once(dev, "%s() called with weight %d\n", __func__,
6298                                 weight);
6299         napi->weight = weight;
6300         napi->dev = dev;
6301 #ifdef CONFIG_NETPOLL
6302         napi->poll_owner = -1;
6303 #endif
6304         set_bit(NAPI_STATE_SCHED, &napi->state);
6305         set_bit(NAPI_STATE_NPSVC, &napi->state);
6306         list_add_rcu(&napi->dev_list, &dev->napi_list);
6307         napi_hash_add(napi);
6308         /* Create kthread for this napi if dev->threaded is set.
6309          * Clear dev->threaded if kthread creation failed so that
6310          * threaded mode will not be enabled in napi_enable().
6311          */
6312         if (dev->threaded && napi_kthread_create(napi))
6313                 dev->threaded = 0;
6314 }
6315 EXPORT_SYMBOL(netif_napi_add);
6316
6317 void napi_disable(struct napi_struct *n)
6318 {
6319         unsigned long val, new;
6320
6321         might_sleep();
6322         set_bit(NAPI_STATE_DISABLE, &n->state);
6323
6324         for ( ; ; ) {
6325                 val = READ_ONCE(n->state);
6326                 if (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)) {
6327                         usleep_range(20, 200);
6328                         continue;
6329                 }
6330
6331                 new = val | NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC;
6332                 new &= ~(NAPIF_STATE_THREADED | NAPIF_STATE_PREFER_BUSY_POLL);
6333
6334                 if (cmpxchg(&n->state, val, new) == val)
6335                         break;
6336         }
6337
6338         hrtimer_cancel(&n->timer);
6339
6340         clear_bit(NAPI_STATE_DISABLE, &n->state);
6341 }
6342 EXPORT_SYMBOL(napi_disable);
6343
6344 /**
6345  *      napi_enable - enable NAPI scheduling
6346  *      @n: NAPI context
6347  *
6348  * Resume NAPI from being scheduled on this context.
6349  * Must be paired with napi_disable.
6350  */
6351 void napi_enable(struct napi_struct *n)
6352 {
6353         unsigned long val, new;
6354
6355         do {
6356                 val = READ_ONCE(n->state);
6357                 BUG_ON(!test_bit(NAPI_STATE_SCHED, &val));
6358
6359                 new = val & ~(NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC);
6360                 if (n->dev->threaded && n->thread)
6361                         new |= NAPIF_STATE_THREADED;
6362         } while (cmpxchg(&n->state, val, new) != val);
6363 }
6364 EXPORT_SYMBOL(napi_enable);
6365
6366 static void flush_gro_hash(struct napi_struct *napi)
6367 {
6368         int i;
6369
6370         for (i = 0; i < GRO_HASH_BUCKETS; i++) {
6371                 struct sk_buff *skb, *n;
6372
6373                 list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
6374                         kfree_skb(skb);
6375                 napi->gro_hash[i].count = 0;
6376         }
6377 }
6378
6379 /* Must be called in process context */
6380 void __netif_napi_del(struct napi_struct *napi)
6381 {
6382         if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
6383                 return;
6384
6385         napi_hash_del(napi);
6386         list_del_rcu(&napi->dev_list);
6387         napi_free_frags(napi);
6388
6389         flush_gro_hash(napi);
6390         napi->gro_bitmask = 0;
6391
6392         if (napi->thread) {
6393                 kthread_stop(napi->thread);
6394                 napi->thread = NULL;
6395         }
6396 }
6397 EXPORT_SYMBOL(__netif_napi_del);
6398
6399 static int __napi_poll(struct napi_struct *n, bool *repoll)
6400 {
6401         int work, weight;
6402
6403         weight = n->weight;
6404
6405         /* This NAPI_STATE_SCHED test is for avoiding a race
6406          * with netpoll's poll_napi().  Only the entity which
6407          * obtains the lock and sees NAPI_STATE_SCHED set will
6408          * actually make the ->poll() call.  Therefore we avoid
6409          * accidentally calling ->poll() when NAPI is not scheduled.
6410          */
6411         work = 0;
6412         if (test_bit(NAPI_STATE_SCHED, &n->state)) {
6413                 work = n->poll(n, weight);
6414                 trace_napi_poll(n, work, weight);
6415         }
6416
6417         if (unlikely(work > weight))
6418                 netdev_err_once(n->dev, "NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
6419                                 n->poll, work, weight);
6420
6421         if (likely(work < weight))
6422                 return work;
6423
6424         /* Drivers must not modify the NAPI state if they
6425          * consume the entire weight.  In such cases this code
6426          * still "owns" the NAPI instance and therefore can
6427          * move the instance around on the list at-will.
6428          */
6429         if (unlikely(napi_disable_pending(n))) {
6430                 napi_complete(n);
6431                 return work;
6432         }
6433
6434         /* The NAPI context has more processing work, but busy-polling
6435          * is preferred. Exit early.
6436          */
6437         if (napi_prefer_busy_poll(n)) {
6438                 if (napi_complete_done(n, work)) {
6439                         /* If timeout is not set, we need to make sure
6440                          * that the NAPI is re-scheduled.
6441                          */
6442                         napi_schedule(n);
6443                 }
6444                 return work;
6445         }
6446
6447         if (n->gro_bitmask) {
6448                 /* flush too old packets
6449                  * If HZ < 1000, flush all packets.
6450                  */
6451                 napi_gro_flush(n, HZ >= 1000);
6452         }
6453
6454         gro_normal_list(n);
6455
6456         /* Some drivers may have called napi_schedule
6457          * prior to exhausting their budget.
6458          */
6459         if (unlikely(!list_empty(&n->poll_list))) {
6460                 pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
6461                              n->dev ? n->dev->name : "backlog");
6462                 return work;
6463         }
6464
6465         *repoll = true;
6466
6467         return work;
6468 }
6469
6470 static int napi_poll(struct napi_struct *n, struct list_head *repoll)
6471 {
6472         bool do_repoll = false;
6473         void *have;
6474         int work;
6475
6476         list_del_init(&n->poll_list);
6477
6478         have = netpoll_poll_lock(n);
6479
6480         work = __napi_poll(n, &do_repoll);
6481
6482         if (do_repoll)
6483                 list_add_tail(&n->poll_list, repoll);
6484
6485         netpoll_poll_unlock(have);
6486
6487         return work;
6488 }
6489
6490 static int napi_thread_wait(struct napi_struct *napi)
6491 {
6492         bool woken = false;
6493
6494         set_current_state(TASK_INTERRUPTIBLE);
6495
6496         while (!kthread_should_stop()) {
6497                 /* Testing SCHED_THREADED bit here to make sure the current
6498                  * kthread owns this napi and could poll on this napi.
6499                  * Testing SCHED bit is not enough because SCHED bit might be
6500                  * set by some other busy poll thread or by napi_disable().
6501                  */
6502                 if (test_bit(NAPI_STATE_SCHED_THREADED, &napi->state) || woken) {
6503                         WARN_ON(!list_empty(&napi->poll_list));
6504                         __set_current_state(TASK_RUNNING);
6505                         return 0;
6506                 }
6507
6508                 schedule();
6509                 /* woken being true indicates this thread owns this napi. */
6510                 woken = true;
6511                 set_current_state(TASK_INTERRUPTIBLE);
6512         }
6513         __set_current_state(TASK_RUNNING);
6514
6515         return -1;
6516 }
6517
6518 static int napi_threaded_poll(void *data)
6519 {
6520         struct napi_struct *napi = data;
6521         void *have;
6522
6523         while (!napi_thread_wait(napi)) {
6524                 for (;;) {
6525                         bool repoll = false;
6526
6527                         local_bh_disable();
6528
6529                         have = netpoll_poll_lock(napi);
6530                         __napi_poll(napi, &repoll);
6531                         netpoll_poll_unlock(have);
6532
6533                         local_bh_enable();
6534
6535                         if (!repoll)
6536                                 break;
6537
6538                         cond_resched();
6539                 }
6540         }
6541         return 0;
6542 }
6543
6544 static __latent_entropy void net_rx_action(struct softirq_action *h)
6545 {
6546         struct softnet_data *sd = this_cpu_ptr(&softnet_data);
6547         unsigned long time_limit = jiffies +
6548                 usecs_to_jiffies(netdev_budget_usecs);
6549         int budget = netdev_budget;
6550         LIST_HEAD(list);
6551         LIST_HEAD(repoll);
6552
6553         local_irq_disable();
6554         list_splice_init(&sd->poll_list, &list);
6555         local_irq_enable();
6556
6557         for (;;) {
6558                 struct napi_struct *n;
6559
6560                 if (list_empty(&list)) {
6561                         if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
6562                                 return;
6563                         break;
6564                 }
6565
6566                 n = list_first_entry(&list, struct napi_struct, poll_list);
6567                 budget -= napi_poll(n, &repoll);
6568
6569                 /* If softirq window is exhausted then punt.
6570                  * Allow this to run for 2 jiffies since which will allow
6571                  * an average latency of 1.5/HZ.
6572                  */
6573                 if (unlikely(budget <= 0 ||
6574                              time_after_eq(jiffies, time_limit))) {
6575                         sd->time_squeeze++;
6576                         break;
6577                 }
6578         }
6579
6580         local_irq_disable();
6581
6582         list_splice_tail_init(&sd->poll_list, &list);
6583         list_splice_tail(&repoll, &list);
6584         list_splice(&list, &sd->poll_list);
6585         if (!list_empty(&sd->poll_list))
6586                 __raise_softirq_irqoff(NET_RX_SOFTIRQ);
6587
6588         net_rps_action_and_irq_enable(sd);
6589 }
6590
6591 struct netdev_adjacent {
6592         struct net_device *dev;
6593         netdevice_tracker dev_tracker;
6594
6595         /* upper master flag, there can only be one master device per list */
6596         bool master;
6597
6598         /* lookup ignore flag */
6599         bool ignore;
6600
6601         /* counter for the number of times this device was added to us */
6602         u16 ref_nr;
6603
6604         /* private field for the users */
6605         void *private;
6606
6607         struct list_head list;
6608         struct rcu_head rcu;
6609 };
6610
6611 static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
6612                                                  struct list_head *adj_list)
6613 {
6614         struct netdev_adjacent *adj;
6615
6616         list_for_each_entry(adj, adj_list, list) {
6617                 if (adj->dev == adj_dev)
6618                         return adj;
6619         }
6620         return NULL;
6621 }
6622
6623 static int ____netdev_has_upper_dev(struct net_device *upper_dev,
6624                                     struct netdev_nested_priv *priv)
6625 {
6626         struct net_device *dev = (struct net_device *)priv->data;
6627
6628         return upper_dev == dev;
6629 }
6630
6631 /**
6632  * netdev_has_upper_dev - Check if device is linked to an upper device
6633  * @dev: device
6634  * @upper_dev: upper device to check
6635  *
6636  * Find out if a device is linked to specified upper device and return true
6637  * in case it is. Note that this checks only immediate upper device,
6638  * not through a complete stack of devices. The caller must hold the RTNL lock.
6639  */
6640 bool netdev_has_upper_dev(struct net_device *dev,
6641                           struct net_device *upper_dev)
6642 {
6643         struct netdev_nested_priv priv = {
6644                 .data = (void *)upper_dev,
6645         };
6646
6647         ASSERT_RTNL();
6648
6649         return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6650                                              &priv);
6651 }
6652 EXPORT_SYMBOL(netdev_has_upper_dev);
6653
6654 /**
6655  * netdev_has_upper_dev_all_rcu - Check if device is linked to an upper device
6656  * @dev: device
6657  * @upper_dev: upper device to check
6658  *
6659  * Find out if a device is linked to specified upper device and return true
6660  * in case it is. Note that this checks the entire upper device chain.
6661  * The caller must hold rcu lock.
6662  */
6663
6664 bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
6665                                   struct net_device *upper_dev)
6666 {
6667         struct netdev_nested_priv priv = {
6668                 .data = (void *)upper_dev,
6669         };
6670
6671         return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
6672                                                &priv);
6673 }
6674 EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
6675
6676 /**
6677  * netdev_has_any_upper_dev - Check if device is linked to some device
6678  * @dev: device
6679  *
6680  * Find out if a device is linked to an upper device and return true in case
6681  * it is. The caller must hold the RTNL lock.
6682  */
6683 bool netdev_has_any_upper_dev(struct net_device *dev)
6684 {
6685         ASSERT_RTNL();
6686
6687         return !list_empty(&dev->adj_list.upper);
6688 }
6689 EXPORT_SYMBOL(netdev_has_any_upper_dev);
6690
6691 /**
6692  * netdev_master_upper_dev_get - Get master upper device
6693  * @dev: device
6694  *
6695  * Find a master upper device and return pointer to it or NULL in case
6696  * it's not there. The caller must hold the RTNL lock.
6697  */
6698 struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
6699 {
6700         struct netdev_adjacent *upper;
6701
6702         ASSERT_RTNL();
6703
6704         if (list_empty(&dev->adj_list.upper))
6705                 return NULL;
6706
6707         upper = list_first_entry(&dev->adj_list.upper,
6708                                  struct netdev_adjacent, list);
6709         if (likely(upper->master))
6710                 return upper->dev;
6711         return NULL;
6712 }
6713 EXPORT_SYMBOL(netdev_master_upper_dev_get);
6714
6715 static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
6716 {
6717         struct netdev_adjacent *upper;
6718
6719         ASSERT_RTNL();
6720
6721         if (list_empty(&dev->adj_list.upper))
6722                 return NULL;
6723
6724         upper = list_first_entry(&dev->adj_list.upper,
6725                                  struct netdev_adjacent, list);
6726         if (likely(upper->master) && !upper->ignore)
6727                 return upper->dev;
6728         return NULL;
6729 }
6730
6731 /**
6732  * netdev_has_any_lower_dev - Check if device is linked to some device
6733  * @dev: device
6734  *
6735  * Find out if a device is linked to a lower device and return true in case
6736  * it is. The caller must hold the RTNL lock.
6737  */
6738 static bool netdev_has_any_lower_dev(struct net_device *dev)
6739 {
6740         ASSERT_RTNL();
6741
6742         return !list_empty(&dev->adj_list.lower);
6743 }
6744
6745 void *netdev_adjacent_get_private(struct list_head *adj_list)
6746 {
6747         struct netdev_adjacent *adj;
6748
6749         adj = list_entry(adj_list, struct netdev_adjacent, list);
6750
6751         return adj->private;
6752 }
6753 EXPORT_SYMBOL(netdev_adjacent_get_private);
6754
6755 /**
6756  * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
6757  * @dev: device
6758  * @iter: list_head ** of the current position
6759  *
6760  * Gets the next device from the dev's upper list, starting from iter
6761  * position. The caller must hold RCU read lock.
6762  */
6763 struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
6764                                                  struct list_head **iter)
6765 {
6766         struct netdev_adjacent *upper;
6767
6768         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6769
6770         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6771
6772         if (&upper->list == &dev->adj_list.upper)
6773                 return NULL;
6774
6775         *iter = &upper->list;
6776
6777         return upper->dev;
6778 }
6779 EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
6780
6781 static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
6782                                                   struct list_head **iter,
6783                                                   bool *ignore)
6784 {
6785         struct netdev_adjacent *upper;
6786
6787         upper = list_entry((*iter)->next, struct netdev_adjacent, list);
6788
6789         if (&upper->list == &dev->adj_list.upper)
6790                 return NULL;
6791
6792         *iter = &upper->list;
6793         *ignore = upper->ignore;
6794
6795         return upper->dev;
6796 }
6797
6798 static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
6799                                                     struct list_head **iter)
6800 {
6801         struct netdev_adjacent *upper;
6802
6803         WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
6804
6805         upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6806
6807         if (&upper->list == &dev->adj_list.upper)
6808                 return NULL;
6809
6810         *iter = &upper->list;
6811
6812         return upper->dev;
6813 }
6814
6815 static int __netdev_walk_all_upper_dev(struct net_device *dev,
6816                                        int (*fn)(struct net_device *dev,
6817                                          struct netdev_nested_priv *priv),
6818                                        struct netdev_nested_priv *priv)
6819 {
6820         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6821         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6822         int ret, cur = 0;
6823         bool ignore;
6824
6825         now = dev;
6826         iter = &dev->adj_list.upper;
6827
6828         while (1) {
6829                 if (now != dev) {
6830                         ret = fn(now, priv);
6831                         if (ret)
6832                                 return ret;
6833                 }
6834
6835                 next = NULL;
6836                 while (1) {
6837                         udev = __netdev_next_upper_dev(now, &iter, &ignore);
6838                         if (!udev)
6839                                 break;
6840                         if (ignore)
6841                                 continue;
6842
6843                         next = udev;
6844                         niter = &udev->adj_list.upper;
6845                         dev_stack[cur] = now;
6846                         iter_stack[cur++] = iter;
6847                         break;
6848                 }
6849
6850                 if (!next) {
6851                         if (!cur)
6852                                 return 0;
6853                         next = dev_stack[--cur];
6854                         niter = iter_stack[cur];
6855                 }
6856
6857                 now = next;
6858                 iter = niter;
6859         }
6860
6861         return 0;
6862 }
6863
6864 int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
6865                                   int (*fn)(struct net_device *dev,
6866                                             struct netdev_nested_priv *priv),
6867                                   struct netdev_nested_priv *priv)
6868 {
6869         struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
6870         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
6871         int ret, cur = 0;
6872
6873         now = dev;
6874         iter = &dev->adj_list.upper;
6875
6876         while (1) {
6877                 if (now != dev) {
6878                         ret = fn(now, priv);
6879                         if (ret)
6880                                 return ret;
6881                 }
6882
6883                 next = NULL;
6884                 while (1) {
6885                         udev = netdev_next_upper_dev_rcu(now, &iter);
6886                         if (!udev)
6887                                 break;
6888
6889                         next = udev;
6890                         niter = &udev->adj_list.upper;
6891                         dev_stack[cur] = now;
6892                         iter_stack[cur++] = iter;
6893                         break;
6894                 }
6895
6896                 if (!next) {
6897                         if (!cur)
6898                                 return 0;
6899                         next = dev_stack[--cur];
6900                         niter = iter_stack[cur];
6901                 }
6902
6903                 now = next;
6904                 iter = niter;
6905         }
6906
6907         return 0;
6908 }
6909 EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
6910
6911 static bool __netdev_has_upper_dev(struct net_device *dev,
6912                                    struct net_device *upper_dev)
6913 {
6914         struct netdev_nested_priv priv = {
6915                 .flags = 0,
6916                 .data = (void *)upper_dev,
6917         };
6918
6919         ASSERT_RTNL();
6920
6921         return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
6922                                            &priv);
6923 }
6924
6925 /**
6926  * netdev_lower_get_next_private - Get the next ->private from the
6927  *                                 lower neighbour list
6928  * @dev: device
6929  * @iter: list_head ** of the current position
6930  *
6931  * Gets the next netdev_adjacent->private from the dev's lower neighbour
6932  * list, starting from iter position. The caller must hold either hold the
6933  * RTNL lock or its own locking that guarantees that the neighbour lower
6934  * list will remain unchanged.
6935  */
6936 void *netdev_lower_get_next_private(struct net_device *dev,
6937                                     struct list_head **iter)
6938 {
6939         struct netdev_adjacent *lower;
6940
6941         lower = list_entry(*iter, struct netdev_adjacent, list);
6942
6943         if (&lower->list == &dev->adj_list.lower)
6944                 return NULL;
6945
6946         *iter = lower->list.next;
6947
6948         return lower->private;
6949 }
6950 EXPORT_SYMBOL(netdev_lower_get_next_private);
6951
6952 /**
6953  * netdev_lower_get_next_private_rcu - Get the next ->private from the
6954  *                                     lower neighbour list, RCU
6955  *                                     variant
6956  * @dev: device
6957  * @iter: list_head ** of the current position
6958  *
6959  * Gets the next netdev_adjacent->private from the dev's lower neighbour
6960  * list, starting from iter position. The caller must hold RCU read lock.
6961  */
6962 void *netdev_lower_get_next_private_rcu(struct net_device *dev,
6963                                         struct list_head **iter)
6964 {
6965         struct netdev_adjacent *lower;
6966
6967         WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
6968
6969         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
6970
6971         if (&lower->list == &dev->adj_list.lower)
6972                 return NULL;
6973
6974         *iter = &lower->list;
6975
6976         return lower->private;
6977 }
6978 EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
6979
6980 /**
6981  * netdev_lower_get_next - Get the next device from the lower neighbour
6982  *                         list
6983  * @dev: device
6984  * @iter: list_head ** of the current position
6985  *
6986  * Gets the next netdev_adjacent from the dev's lower neighbour
6987  * list, starting from iter position. The caller must hold RTNL lock or
6988  * its own locking that guarantees that the neighbour lower
6989  * list will remain unchanged.
6990  */
6991 void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
6992 {
6993         struct netdev_adjacent *lower;
6994
6995         lower = list_entry(*iter, struct netdev_adjacent, list);
6996
6997         if (&lower->list == &dev->adj_list.lower)
6998                 return NULL;
6999
7000         *iter = lower->list.next;
7001
7002         return lower->dev;
7003 }
7004 EXPORT_SYMBOL(netdev_lower_get_next);
7005
7006 static struct net_device *netdev_next_lower_dev(struct net_device *dev,
7007                                                 struct list_head **iter)
7008 {
7009         struct netdev_adjacent *lower;
7010
7011         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7012
7013         if (&lower->list == &dev->adj_list.lower)
7014                 return NULL;
7015
7016         *iter = &lower->list;
7017
7018         return lower->dev;
7019 }
7020
7021 static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
7022                                                   struct list_head **iter,
7023                                                   bool *ignore)
7024 {
7025         struct netdev_adjacent *lower;
7026
7027         lower = list_entry((*iter)->next, struct netdev_adjacent, list);
7028
7029         if (&lower->list == &dev->adj_list.lower)
7030                 return NULL;
7031
7032         *iter = &lower->list;
7033         *ignore = lower->ignore;
7034
7035         return lower->dev;
7036 }
7037
7038 int netdev_walk_all_lower_dev(struct net_device *dev,
7039                               int (*fn)(struct net_device *dev,
7040                                         struct netdev_nested_priv *priv),
7041                               struct netdev_nested_priv *priv)
7042 {
7043         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7044         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7045         int ret, cur = 0;
7046
7047         now = dev;
7048         iter = &dev->adj_list.lower;
7049
7050         while (1) {
7051                 if (now != dev) {
7052                         ret = fn(now, priv);
7053                         if (ret)
7054                                 return ret;
7055                 }
7056
7057                 next = NULL;
7058                 while (1) {
7059                         ldev = netdev_next_lower_dev(now, &iter);
7060                         if (!ldev)
7061                                 break;
7062
7063                         next = ldev;
7064                         niter = &ldev->adj_list.lower;
7065                         dev_stack[cur] = now;
7066                         iter_stack[cur++] = iter;
7067                         break;
7068                 }
7069
7070                 if (!next) {
7071                         if (!cur)
7072                                 return 0;
7073                         next = dev_stack[--cur];
7074                         niter = iter_stack[cur];
7075                 }
7076
7077                 now = next;
7078                 iter = niter;
7079         }
7080
7081         return 0;
7082 }
7083 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
7084
7085 static int __netdev_walk_all_lower_dev(struct net_device *dev,
7086                                        int (*fn)(struct net_device *dev,
7087                                          struct netdev_nested_priv *priv),
7088                                        struct netdev_nested_priv *priv)
7089 {
7090         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7091         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7092         int ret, cur = 0;
7093         bool ignore;
7094
7095         now = dev;
7096         iter = &dev->adj_list.lower;
7097
7098         while (1) {
7099                 if (now != dev) {
7100                         ret = fn(now, priv);
7101                         if (ret)
7102                                 return ret;
7103                 }
7104
7105                 next = NULL;
7106                 while (1) {
7107                         ldev = __netdev_next_lower_dev(now, &iter, &ignore);
7108                         if (!ldev)
7109                                 break;
7110                         if (ignore)
7111                                 continue;
7112
7113                         next = ldev;
7114                         niter = &ldev->adj_list.lower;
7115                         dev_stack[cur] = now;
7116                         iter_stack[cur++] = iter;
7117                         break;
7118                 }
7119
7120                 if (!next) {
7121                         if (!cur)
7122                                 return 0;
7123                         next = dev_stack[--cur];
7124                         niter = iter_stack[cur];
7125                 }
7126
7127                 now = next;
7128                 iter = niter;
7129         }
7130
7131         return 0;
7132 }
7133
7134 struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
7135                                              struct list_head **iter)
7136 {
7137         struct netdev_adjacent *lower;
7138
7139         lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
7140         if (&lower->list == &dev->adj_list.lower)
7141                 return NULL;
7142
7143         *iter = &lower->list;
7144
7145         return lower->dev;
7146 }
7147 EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
7148
7149 static u8 __netdev_upper_depth(struct net_device *dev)
7150 {
7151         struct net_device *udev;
7152         struct list_head *iter;
7153         u8 max_depth = 0;
7154         bool ignore;
7155
7156         for (iter = &dev->adj_list.upper,
7157              udev = __netdev_next_upper_dev(dev, &iter, &ignore);
7158              udev;
7159              udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
7160                 if (ignore)
7161                         continue;
7162                 if (max_depth < udev->upper_level)
7163                         max_depth = udev->upper_level;
7164         }
7165
7166         return max_depth;
7167 }
7168
7169 static u8 __netdev_lower_depth(struct net_device *dev)
7170 {
7171         struct net_device *ldev;
7172         struct list_head *iter;
7173         u8 max_depth = 0;
7174         bool ignore;
7175
7176         for (iter = &dev->adj_list.lower,
7177              ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
7178              ldev;
7179              ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
7180                 if (ignore)
7181                         continue;
7182                 if (max_depth < ldev->lower_level)
7183                         max_depth = ldev->lower_level;
7184         }
7185
7186         return max_depth;
7187 }
7188
7189 static int __netdev_update_upper_level(struct net_device *dev,
7190                                        struct netdev_nested_priv *__unused)
7191 {
7192         dev->upper_level = __netdev_upper_depth(dev) + 1;
7193         return 0;
7194 }
7195
7196 #ifdef CONFIG_LOCKDEP
7197 static LIST_HEAD(net_unlink_list);
7198
7199 static void net_unlink_todo(struct net_device *dev)
7200 {
7201         if (list_empty(&dev->unlink_list))
7202                 list_add_tail(&dev->unlink_list, &net_unlink_list);
7203 }
7204 #endif
7205
7206 static int __netdev_update_lower_level(struct net_device *dev,
7207                                        struct netdev_nested_priv *priv)
7208 {
7209         dev->lower_level = __netdev_lower_depth(dev) + 1;
7210
7211 #ifdef CONFIG_LOCKDEP
7212         if (!priv)
7213                 return 0;
7214
7215         if (priv->flags & NESTED_SYNC_IMM)
7216                 dev->nested_level = dev->lower_level - 1;
7217         if (priv->flags & NESTED_SYNC_TODO)
7218                 net_unlink_todo(dev);
7219 #endif
7220         return 0;
7221 }
7222
7223 int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
7224                                   int (*fn)(struct net_device *dev,
7225                                             struct netdev_nested_priv *priv),
7226                                   struct netdev_nested_priv *priv)
7227 {
7228         struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
7229         struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
7230         int ret, cur = 0;
7231
7232         now = dev;
7233         iter = &dev->adj_list.lower;
7234
7235         while (1) {
7236                 if (now != dev) {
7237                         ret = fn(now, priv);
7238                         if (ret)
7239                                 return ret;
7240                 }
7241
7242                 next = NULL;
7243                 while (1) {
7244                         ldev = netdev_next_lower_dev_rcu(now, &iter);
7245                         if (!ldev)
7246                                 break;
7247
7248                         next = ldev;
7249                         niter = &ldev->adj_list.lower;
7250                         dev_stack[cur] = now;
7251                         iter_stack[cur++] = iter;
7252                         break;
7253                 }
7254
7255                 if (!next) {
7256                         if (!cur)
7257                                 return 0;
7258                         next = dev_stack[--cur];
7259                         niter = iter_stack[cur];
7260                 }
7261
7262                 now = next;
7263                 iter = niter;
7264         }
7265
7266         return 0;
7267 }
7268 EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
7269
7270 /**
7271  * netdev_lower_get_first_private_rcu - Get the first ->private from the
7272  *                                     lower neighbour list, RCU
7273  *                                     variant
7274  * @dev: device
7275  *
7276  * Gets the first netdev_adjacent->private from the dev's lower neighbour
7277  * list. The caller must hold RCU read lock.
7278  */
7279 void *netdev_lower_get_first_private_rcu(struct net_device *dev)
7280 {
7281         struct netdev_adjacent *lower;
7282
7283         lower = list_first_or_null_rcu(&dev->adj_list.lower,
7284                         struct netdev_adjacent, list);
7285         if (lower)
7286                 return lower->private;
7287         return NULL;
7288 }
7289 EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
7290
7291 /**
7292  * netdev_master_upper_dev_get_rcu - Get master upper device
7293  * @dev: device
7294  *
7295  * Find a master upper device and return pointer to it or NULL in case
7296  * it's not there. The caller must hold the RCU read lock.
7297  */
7298 struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
7299 {
7300         struct netdev_adjacent *upper;
7301
7302         upper = list_first_or_null_rcu(&dev->adj_list.upper,
7303                                        struct netdev_adjacent, list);
7304         if (upper && likely(upper->master))
7305                 return upper->dev;
7306         return NULL;
7307 }
7308 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
7309
7310 static int netdev_adjacent_sysfs_add(struct net_device *dev,
7311                               struct net_device *adj_dev,
7312                               struct list_head *dev_list)
7313 {
7314         char linkname[IFNAMSIZ+7];
7315
7316         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7317                 "upper_%s" : "lower_%s", adj_dev->name);
7318         return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
7319                                  linkname);
7320 }
7321 static void netdev_adjacent_sysfs_del(struct net_device *dev,
7322                                char *name,
7323                                struct list_head *dev_list)
7324 {
7325         char linkname[IFNAMSIZ+7];
7326
7327         sprintf(linkname, dev_list == &dev->adj_list.upper ?
7328                 "upper_%s" : "lower_%s", name);
7329         sysfs_remove_link(&(dev->dev.kobj), linkname);
7330 }
7331
7332 static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
7333                                                  struct net_device *adj_dev,
7334                                                  struct list_head *dev_list)
7335 {
7336         return (dev_list == &dev->adj_list.upper ||
7337                 dev_list == &dev->adj_list.lower) &&
7338                 net_eq(dev_net(dev), dev_net(adj_dev));
7339 }
7340
7341 static int __netdev_adjacent_dev_insert(struct net_device *dev,
7342                                         struct net_device *adj_dev,
7343                                         struct list_head *dev_list,
7344                                         void *private, bool master)
7345 {
7346         struct netdev_adjacent *adj;
7347         int ret;
7348
7349         adj = __netdev_find_adj(adj_dev, dev_list);
7350
7351         if (adj) {
7352                 adj->ref_nr += 1;
7353                 pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
7354                          dev->name, adj_dev->name, adj->ref_nr);
7355
7356                 return 0;
7357         }
7358
7359         adj = kmalloc(sizeof(*adj), GFP_KERNEL);
7360         if (!adj)
7361                 return -ENOMEM;
7362
7363         adj->dev = adj_dev;
7364         adj->master = master;
7365         adj->ref_nr = 1;
7366         adj->private = private;
7367         adj->ignore = false;
7368         dev_hold_track(adj_dev, &adj->dev_tracker, GFP_KERNEL);
7369
7370         pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
7371                  dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
7372
7373         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
7374                 ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
7375                 if (ret)
7376                         goto free_adj;
7377         }
7378
7379         /* Ensure that master link is always the first item in list. */
7380         if (master) {
7381                 ret = sysfs_create_link(&(dev->dev.kobj),
7382                                         &(adj_dev->dev.kobj), "master");
7383                 if (ret)
7384                         goto remove_symlinks;
7385
7386                 list_add_rcu(&adj->list, dev_list);
7387         } else {
7388                 list_add_tail_rcu(&adj->list, dev_list);
7389         }
7390
7391         return 0;
7392
7393 remove_symlinks:
7394         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7395                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7396 free_adj:
7397         dev_put_track(adj_dev, &adj->dev_tracker);
7398         kfree(adj);
7399
7400         return ret;
7401 }
7402
7403 static void __netdev_adjacent_dev_remove(struct net_device *dev,
7404                                          struct net_device *adj_dev,
7405                                          u16 ref_nr,
7406                                          struct list_head *dev_list)
7407 {
7408         struct netdev_adjacent *adj;
7409
7410         pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
7411                  dev->name, adj_dev->name, ref_nr);
7412
7413         adj = __netdev_find_adj(adj_dev, dev_list);
7414
7415         if (!adj) {
7416                 pr_err("Adjacency does not exist for device %s from %s\n",
7417                        dev->name, adj_dev->name);
7418                 WARN_ON(1);
7419                 return;
7420         }
7421
7422         if (adj->ref_nr > ref_nr) {
7423                 pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
7424                          dev->name, adj_dev->name, ref_nr,
7425                          adj->ref_nr - ref_nr);
7426                 adj->ref_nr -= ref_nr;
7427                 return;
7428         }
7429
7430         if (adj->master)
7431                 sysfs_remove_link(&(dev->dev.kobj), "master");
7432
7433         if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
7434                 netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
7435
7436         list_del_rcu(&adj->list);
7437         pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
7438                  adj_dev->name, dev->name, adj_dev->name);
7439         dev_put_track(adj_dev, &adj->dev_tracker);
7440         kfree_rcu(adj, rcu);
7441 }
7442
7443 static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
7444                                             struct net_device *upper_dev,
7445                                             struct list_head *up_list,
7446                                             struct list_head *down_list,
7447                                             void *private, bool master)
7448 {
7449         int ret;
7450
7451         ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
7452                                            private, master);
7453         if (ret)
7454                 return ret;
7455
7456         ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
7457                                            private, false);
7458         if (ret) {
7459                 __netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
7460                 return ret;
7461         }
7462
7463         return 0;
7464 }
7465
7466 static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
7467                                                struct net_device *upper_dev,
7468                                                u16 ref_nr,
7469                                                struct list_head *up_list,
7470                                                struct list_head *down_list)
7471 {
7472         __netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
7473         __netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
7474 }
7475
7476 static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
7477                                                 struct net_device *upper_dev,
7478                                                 void *private, bool master)
7479 {
7480         return __netdev_adjacent_dev_link_lists(dev, upper_dev,
7481                                                 &dev->adj_list.upper,
7482                                                 &upper_dev->adj_list.lower,
7483                                                 private, master);
7484 }
7485
7486 static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
7487                                                    struct net_device *upper_dev)
7488 {
7489         __netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
7490                                            &dev->adj_list.upper,
7491                                            &upper_dev->adj_list.lower);
7492 }
7493
7494 static int __netdev_upper_dev_link(struct net_device *dev,
7495                                    struct net_device *upper_dev, bool master,
7496                                    void *upper_priv, void *upper_info,
7497                                    struct netdev_nested_priv *priv,
7498                                    struct netlink_ext_ack *extack)
7499 {
7500         struct netdev_notifier_changeupper_info changeupper_info = {
7501                 .info = {
7502                         .dev = dev,
7503                         .extack = extack,
7504                 },
7505                 .upper_dev = upper_dev,
7506                 .master = master,
7507                 .linking = true,
7508                 .upper_info = upper_info,
7509         };
7510         struct net_device *master_dev;
7511         int ret = 0;
7512
7513         ASSERT_RTNL();
7514
7515         if (dev == upper_dev)
7516                 return -EBUSY;
7517
7518         /* To prevent loops, check if dev is not upper device to upper_dev. */
7519         if (__netdev_has_upper_dev(upper_dev, dev))
7520                 return -EBUSY;
7521
7522         if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
7523                 return -EMLINK;
7524
7525         if (!master) {
7526                 if (__netdev_has_upper_dev(dev, upper_dev))
7527                         return -EEXIST;
7528         } else {
7529                 master_dev = __netdev_master_upper_dev_get(dev);
7530                 if (master_dev)
7531                         return master_dev == upper_dev ? -EEXIST : -EBUSY;
7532         }
7533
7534         ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7535                                             &changeupper_info.info);
7536         ret = notifier_to_errno(ret);
7537         if (ret)
7538                 return ret;
7539
7540         ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
7541                                                    master);
7542         if (ret)
7543                 return ret;
7544
7545         ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7546                                             &changeupper_info.info);
7547         ret = notifier_to_errno(ret);
7548         if (ret)
7549                 goto rollback;
7550
7551         __netdev_update_upper_level(dev, NULL);
7552         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7553
7554         __netdev_update_lower_level(upper_dev, priv);
7555         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7556                                     priv);
7557
7558         return 0;
7559
7560 rollback:
7561         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7562
7563         return ret;
7564 }
7565
7566 /**
7567  * netdev_upper_dev_link - Add a link to the upper device
7568  * @dev: device
7569  * @upper_dev: new upper device
7570  * @extack: netlink extended ack
7571  *
7572  * Adds a link to device which is upper to this one. The caller must hold
7573  * the RTNL lock. On a failure a negative errno code is returned.
7574  * On success the reference counts are adjusted and the function
7575  * returns zero.
7576  */
7577 int netdev_upper_dev_link(struct net_device *dev,
7578                           struct net_device *upper_dev,
7579                           struct netlink_ext_ack *extack)
7580 {
7581         struct netdev_nested_priv priv = {
7582                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7583                 .data = NULL,
7584         };
7585
7586         return __netdev_upper_dev_link(dev, upper_dev, false,
7587                                        NULL, NULL, &priv, extack);
7588 }
7589 EXPORT_SYMBOL(netdev_upper_dev_link);
7590
7591 /**
7592  * netdev_master_upper_dev_link - Add a master link to the upper device
7593  * @dev: device
7594  * @upper_dev: new upper device
7595  * @upper_priv: upper device private
7596  * @upper_info: upper info to be passed down via notifier
7597  * @extack: netlink extended ack
7598  *
7599  * Adds a link to device which is upper to this one. In this case, only
7600  * one master upper device can be linked, although other non-master devices
7601  * might be linked as well. The caller must hold the RTNL lock.
7602  * On a failure a negative errno code is returned. On success the reference
7603  * counts are adjusted and the function returns zero.
7604  */
7605 int netdev_master_upper_dev_link(struct net_device *dev,
7606                                  struct net_device *upper_dev,
7607                                  void *upper_priv, void *upper_info,
7608                                  struct netlink_ext_ack *extack)
7609 {
7610         struct netdev_nested_priv priv = {
7611                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7612                 .data = NULL,
7613         };
7614
7615         return __netdev_upper_dev_link(dev, upper_dev, true,
7616                                        upper_priv, upper_info, &priv, extack);
7617 }
7618 EXPORT_SYMBOL(netdev_master_upper_dev_link);
7619
7620 static void __netdev_upper_dev_unlink(struct net_device *dev,
7621                                       struct net_device *upper_dev,
7622                                       struct netdev_nested_priv *priv)
7623 {
7624         struct netdev_notifier_changeupper_info changeupper_info = {
7625                 .info = {
7626                         .dev = dev,
7627                 },
7628                 .upper_dev = upper_dev,
7629                 .linking = false,
7630         };
7631
7632         ASSERT_RTNL();
7633
7634         changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
7635
7636         call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
7637                                       &changeupper_info.info);
7638
7639         __netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
7640
7641         call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
7642                                       &changeupper_info.info);
7643
7644         __netdev_update_upper_level(dev, NULL);
7645         __netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
7646
7647         __netdev_update_lower_level(upper_dev, priv);
7648         __netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
7649                                     priv);
7650 }
7651
7652 /**
7653  * netdev_upper_dev_unlink - Removes a link to upper device
7654  * @dev: device
7655  * @upper_dev: new upper device
7656  *
7657  * Removes a link to device which is upper to this one. The caller must hold
7658  * the RTNL lock.
7659  */
7660 void netdev_upper_dev_unlink(struct net_device *dev,
7661                              struct net_device *upper_dev)
7662 {
7663         struct netdev_nested_priv priv = {
7664                 .flags = NESTED_SYNC_TODO,
7665                 .data = NULL,
7666         };
7667
7668         __netdev_upper_dev_unlink(dev, upper_dev, &priv);
7669 }
7670 EXPORT_SYMBOL(netdev_upper_dev_unlink);
7671
7672 static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
7673                                       struct net_device *lower_dev,
7674                                       bool val)
7675 {
7676         struct netdev_adjacent *adj;
7677
7678         adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
7679         if (adj)
7680                 adj->ignore = val;
7681
7682         adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
7683         if (adj)
7684                 adj->ignore = val;
7685 }
7686
7687 static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
7688                                         struct net_device *lower_dev)
7689 {
7690         __netdev_adjacent_dev_set(upper_dev, lower_dev, true);
7691 }
7692
7693 static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
7694                                        struct net_device *lower_dev)
7695 {
7696         __netdev_adjacent_dev_set(upper_dev, lower_dev, false);
7697 }
7698
7699 int netdev_adjacent_change_prepare(struct net_device *old_dev,
7700                                    struct net_device *new_dev,
7701                                    struct net_device *dev,
7702                                    struct netlink_ext_ack *extack)
7703 {
7704         struct netdev_nested_priv priv = {
7705                 .flags = 0,
7706                 .data = NULL,
7707         };
7708         int err;
7709
7710         if (!new_dev)
7711                 return 0;
7712
7713         if (old_dev && new_dev != old_dev)
7714                 netdev_adjacent_dev_disable(dev, old_dev);
7715         err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
7716                                       extack);
7717         if (err) {
7718                 if (old_dev && new_dev != old_dev)
7719                         netdev_adjacent_dev_enable(dev, old_dev);
7720                 return err;
7721         }
7722
7723         return 0;
7724 }
7725 EXPORT_SYMBOL(netdev_adjacent_change_prepare);
7726
7727 void netdev_adjacent_change_commit(struct net_device *old_dev,
7728                                    struct net_device *new_dev,
7729                                    struct net_device *dev)
7730 {
7731         struct netdev_nested_priv priv = {
7732                 .flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
7733                 .data = NULL,
7734         };
7735
7736         if (!new_dev || !old_dev)
7737                 return;
7738
7739         if (new_dev == old_dev)
7740                 return;
7741
7742         netdev_adjacent_dev_enable(dev, old_dev);
7743         __netdev_upper_dev_unlink(old_dev, dev, &priv);
7744 }
7745 EXPORT_SYMBOL(netdev_adjacent_change_commit);
7746
7747 void netdev_adjacent_change_abort(struct net_device *old_dev,
7748                                   struct net_device *new_dev,
7749                                   struct net_device *dev)
7750 {
7751         struct netdev_nested_priv priv = {
7752                 .flags = 0,
7753                 .data = NULL,
7754         };
7755
7756         if (!new_dev)
7757                 return;
7758
7759         if (old_dev && new_dev != old_dev)
7760                 netdev_adjacent_dev_enable(dev, old_dev);
7761
7762         __netdev_upper_dev_unlink(new_dev, dev, &priv);
7763 }
7764 EXPORT_SYMBOL(netdev_adjacent_change_abort);
7765
7766 /**
7767  * netdev_bonding_info_change - Dispatch event about slave change
7768  * @dev: device
7769  * @bonding_info: info to dispatch
7770  *
7771  * Send NETDEV_BONDING_INFO to netdev notifiers with info.
7772  * The caller must hold the RTNL lock.
7773  */
7774 void netdev_bonding_info_change(struct net_device *dev,
7775                                 struct netdev_bonding_info *bonding_info)
7776 {
7777         struct netdev_notifier_bonding_info info = {
7778                 .info.dev = dev,
7779         };
7780
7781         memcpy(&info.bonding_info, bonding_info,
7782                sizeof(struct netdev_bonding_info));
7783         call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
7784                                       &info.info);
7785 }
7786 EXPORT_SYMBOL(netdev_bonding_info_change);
7787
7788 static int netdev_offload_xstats_enable_l3(struct net_device *dev,
7789                                            struct netlink_ext_ack *extack)
7790 {
7791         struct netdev_notifier_offload_xstats_info info = {
7792                 .info.dev = dev,
7793                 .info.extack = extack,
7794                 .type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7795         };
7796         int err;
7797         int rc;
7798
7799         dev->offload_xstats_l3 = kzalloc(sizeof(*dev->offload_xstats_l3),
7800                                          GFP_KERNEL);
7801         if (!dev->offload_xstats_l3)
7802                 return -ENOMEM;
7803
7804         rc = call_netdevice_notifiers_info_robust(NETDEV_OFFLOAD_XSTATS_ENABLE,
7805                                                   NETDEV_OFFLOAD_XSTATS_DISABLE,
7806                                                   &info.info);
7807         err = notifier_to_errno(rc);
7808         if (err)
7809                 goto free_stats;
7810
7811         return 0;
7812
7813 free_stats:
7814         kfree(dev->offload_xstats_l3);
7815         dev->offload_xstats_l3 = NULL;
7816         return err;
7817 }
7818
7819 int netdev_offload_xstats_enable(struct net_device *dev,
7820                                  enum netdev_offload_xstats_type type,
7821                                  struct netlink_ext_ack *extack)
7822 {
7823         ASSERT_RTNL();
7824
7825         if (netdev_offload_xstats_enabled(dev, type))
7826                 return -EALREADY;
7827
7828         switch (type) {
7829         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7830                 return netdev_offload_xstats_enable_l3(dev, extack);
7831         }
7832
7833         WARN_ON(1);
7834         return -EINVAL;
7835 }
7836 EXPORT_SYMBOL(netdev_offload_xstats_enable);
7837
7838 static void netdev_offload_xstats_disable_l3(struct net_device *dev)
7839 {
7840         struct netdev_notifier_offload_xstats_info info = {
7841                 .info.dev = dev,
7842                 .type = NETDEV_OFFLOAD_XSTATS_TYPE_L3,
7843         };
7844
7845         call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_DISABLE,
7846                                       &info.info);
7847         kfree(dev->offload_xstats_l3);
7848         dev->offload_xstats_l3 = NULL;
7849 }
7850
7851 int netdev_offload_xstats_disable(struct net_device *dev,
7852                                   enum netdev_offload_xstats_type type)
7853 {
7854         ASSERT_RTNL();
7855
7856         if (!netdev_offload_xstats_enabled(dev, type))
7857                 return -EALREADY;
7858
7859         switch (type) {
7860         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7861                 netdev_offload_xstats_disable_l3(dev);
7862                 return 0;
7863         }
7864
7865         WARN_ON(1);
7866         return -EINVAL;
7867 }
7868 EXPORT_SYMBOL(netdev_offload_xstats_disable);
7869
7870 static void netdev_offload_xstats_disable_all(struct net_device *dev)
7871 {
7872         netdev_offload_xstats_disable(dev, NETDEV_OFFLOAD_XSTATS_TYPE_L3);
7873 }
7874
7875 static struct rtnl_hw_stats64 *
7876 netdev_offload_xstats_get_ptr(const struct net_device *dev,
7877                               enum netdev_offload_xstats_type type)
7878 {
7879         switch (type) {
7880         case NETDEV_OFFLOAD_XSTATS_TYPE_L3:
7881                 return dev->offload_xstats_l3;
7882         }
7883
7884         WARN_ON(1);
7885         return NULL;
7886 }
7887
7888 bool netdev_offload_xstats_enabled(const struct net_device *dev,
7889                                    enum netdev_offload_xstats_type type)
7890 {
7891         ASSERT_RTNL();
7892
7893         return netdev_offload_xstats_get_ptr(dev, type);
7894 }
7895 EXPORT_SYMBOL(netdev_offload_xstats_enabled);
7896
7897 struct netdev_notifier_offload_xstats_ru {
7898         bool used;
7899 };
7900
7901 struct netdev_notifier_offload_xstats_rd {
7902         struct rtnl_hw_stats64 stats;
7903         bool used;
7904 };
7905
7906 static void netdev_hw_stats64_add(struct rtnl_hw_stats64 *dest,
7907                                   const struct rtnl_hw_stats64 *src)
7908 {
7909         dest->rx_packets          += src->rx_packets;
7910         dest->tx_packets          += src->tx_packets;
7911         dest->rx_bytes            += src->rx_bytes;
7912         dest->tx_bytes            += src->tx_bytes;
7913         dest->rx_errors           += src->rx_errors;
7914         dest->tx_errors           += src->tx_errors;
7915         dest->rx_dropped          += src->rx_dropped;
7916         dest->tx_dropped          += src->tx_dropped;
7917         dest->multicast           += src->multicast;
7918 }
7919
7920 static int netdev_offload_xstats_get_used(struct net_device *dev,
7921                                           enum netdev_offload_xstats_type type,
7922                                           bool *p_used,
7923                                           struct netlink_ext_ack *extack)
7924 {
7925         struct netdev_notifier_offload_xstats_ru report_used = {};
7926         struct netdev_notifier_offload_xstats_info info = {
7927                 .info.dev = dev,
7928                 .info.extack = extack,
7929                 .type = type,
7930                 .report_used = &report_used,
7931         };
7932         int rc;
7933
7934         WARN_ON(!netdev_offload_xstats_enabled(dev, type));
7935         rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_USED,
7936                                            &info.info);
7937         *p_used = report_used.used;
7938         return notifier_to_errno(rc);
7939 }
7940
7941 static int netdev_offload_xstats_get_stats(struct net_device *dev,
7942                                            enum netdev_offload_xstats_type type,
7943                                            struct rtnl_hw_stats64 *p_stats,
7944                                            bool *p_used,
7945                                            struct netlink_ext_ack *extack)
7946 {
7947         struct netdev_notifier_offload_xstats_rd report_delta = {};
7948         struct netdev_notifier_offload_xstats_info info = {
7949                 .info.dev = dev,
7950                 .info.extack = extack,
7951                 .type = type,
7952                 .report_delta = &report_delta,
7953         };
7954         struct rtnl_hw_stats64 *stats;
7955         int rc;
7956
7957         stats = netdev_offload_xstats_get_ptr(dev, type);
7958         if (WARN_ON(!stats))
7959                 return -EINVAL;
7960
7961         rc = call_netdevice_notifiers_info(NETDEV_OFFLOAD_XSTATS_REPORT_DELTA,
7962                                            &info.info);
7963
7964         /* Cache whatever we got, even if there was an error, otherwise the
7965          * successful stats retrievals would get lost.
7966          */
7967         netdev_hw_stats64_add(stats, &report_delta.stats);
7968
7969         if (p_stats)
7970                 *p_stats = *stats;
7971         *p_used = report_delta.used;
7972
7973         return notifier_to_errno(rc);
7974 }
7975
7976 int netdev_offload_xstats_get(struct net_device *dev,
7977                               enum netdev_offload_xstats_type type,
7978                               struct rtnl_hw_stats64 *p_stats, bool *p_used,
7979                               struct netlink_ext_ack *extack)
7980 {
7981         ASSERT_RTNL();
7982
7983         if (p_stats)
7984                 return netdev_offload_xstats_get_stats(dev, type, p_stats,
7985                                                        p_used, extack);
7986         else
7987                 return netdev_offload_xstats_get_used(dev, type, p_used,
7988                                                       extack);
7989 }
7990 EXPORT_SYMBOL(netdev_offload_xstats_get);
7991
7992 void
7993 netdev_offload_xstats_report_delta(struct netdev_notifier_offload_xstats_rd *report_delta,
7994                                    const struct rtnl_hw_stats64 *stats)
7995 {
7996         report_delta->used = true;
7997         netdev_hw_stats64_add(&report_delta->stats, stats);
7998 }
7999 EXPORT_SYMBOL(netdev_offload_xstats_report_delta);
8000
8001 void
8002 netdev_offload_xstats_report_used(struct netdev_notifier_offload_xstats_ru *report_used)
8003 {
8004         report_used->used = true;
8005 }
8006 EXPORT_SYMBOL(netdev_offload_xstats_report_used);
8007
8008 void netdev_offload_xstats_push_delta(struct net_device *dev,
8009                                       enum netdev_offload_xstats_type type,
8010                                       const struct rtnl_hw_stats64 *p_stats)
8011 {
8012         struct rtnl_hw_stats64 *stats;
8013
8014         ASSERT_RTNL();
8015
8016         stats = netdev_offload_xstats_get_ptr(dev, type);
8017         if (WARN_ON(!stats))
8018                 return;
8019
8020         netdev_hw_stats64_add(stats, p_stats);
8021 }
8022 EXPORT_SYMBOL(netdev_offload_xstats_push_delta);
8023
8024 /**
8025  * netdev_get_xmit_slave - Get the xmit slave of master device
8026  * @dev: device
8027  * @skb: The packet
8028  * @all_slaves: assume all the slaves are active
8029  *
8030  * The reference counters are not incremented so the caller must be
8031  * careful with locks. The caller must hold RCU lock.
8032  * %NULL is returned if no slave is found.
8033  */
8034
8035 struct net_device *netdev_get_xmit_slave(struct net_device *dev,
8036                                          struct sk_buff *skb,
8037                                          bool all_slaves)
8038 {
8039         const struct net_device_ops *ops = dev->netdev_ops;
8040
8041         if (!ops->ndo_get_xmit_slave)
8042                 return NULL;
8043         return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
8044 }
8045 EXPORT_SYMBOL(netdev_get_xmit_slave);
8046
8047 static struct net_device *netdev_sk_get_lower_dev(struct net_device *dev,
8048                                                   struct sock *sk)
8049 {
8050         const struct net_device_ops *ops = dev->netdev_ops;
8051
8052         if (!ops->ndo_sk_get_lower_dev)
8053                 return NULL;
8054         return ops->ndo_sk_get_lower_dev(dev, sk);
8055 }
8056
8057 /**
8058  * netdev_sk_get_lowest_dev - Get the lowest device in chain given device and socket
8059  * @dev: device
8060  * @sk: the socket
8061  *
8062  * %NULL is returned if no lower device is found.
8063  */
8064
8065 struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,
8066                                             struct sock *sk)
8067 {
8068         struct net_device *lower;
8069
8070         lower = netdev_sk_get_lower_dev(dev, sk);
8071         while (lower) {
8072                 dev = lower;
8073                 lower = netdev_sk_get_lower_dev(dev, sk);
8074         }
8075
8076         return dev;
8077 }
8078 EXPORT_SYMBOL(netdev_sk_get_lowest_dev);
8079
8080 static void netdev_adjacent_add_links(struct net_device *dev)
8081 {
8082         struct netdev_adjacent *iter;
8083
8084         struct net *net = dev_net(dev);
8085
8086         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8087                 if (!net_eq(net, dev_net(iter->dev)))
8088                         continue;
8089                 netdev_adjacent_sysfs_add(iter->dev, dev,
8090                                           &iter->dev->adj_list.lower);
8091                 netdev_adjacent_sysfs_add(dev, iter->dev,
8092                                           &dev->adj_list.upper);
8093         }
8094
8095         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8096                 if (!net_eq(net, dev_net(iter->dev)))
8097                         continue;
8098                 netdev_adjacent_sysfs_add(iter->dev, dev,
8099                                           &iter->dev->adj_list.upper);
8100                 netdev_adjacent_sysfs_add(dev, iter->dev,
8101                                           &dev->adj_list.lower);
8102         }
8103 }
8104
8105 static void netdev_adjacent_del_links(struct net_device *dev)
8106 {
8107         struct netdev_adjacent *iter;
8108
8109         struct net *net = dev_net(dev);
8110
8111         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8112                 if (!net_eq(net, dev_net(iter->dev)))
8113                         continue;
8114                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8115                                           &iter->dev->adj_list.lower);
8116                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8117                                           &dev->adj_list.upper);
8118         }
8119
8120         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8121                 if (!net_eq(net, dev_net(iter->dev)))
8122                         continue;
8123                 netdev_adjacent_sysfs_del(iter->dev, dev->name,
8124                                           &iter->dev->adj_list.upper);
8125                 netdev_adjacent_sysfs_del(dev, iter->dev->name,
8126                                           &dev->adj_list.lower);
8127         }
8128 }
8129
8130 void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
8131 {
8132         struct netdev_adjacent *iter;
8133
8134         struct net *net = dev_net(dev);
8135
8136         list_for_each_entry(iter, &dev->adj_list.upper, list) {
8137                 if (!net_eq(net, dev_net(iter->dev)))
8138                         continue;
8139                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8140                                           &iter->dev->adj_list.lower);
8141                 netdev_adjacent_sysfs_add(iter->dev, dev,
8142                                           &iter->dev->adj_list.lower);
8143         }
8144
8145         list_for_each_entry(iter, &dev->adj_list.lower, list) {
8146                 if (!net_eq(net, dev_net(iter->dev)))
8147                         continue;
8148                 netdev_adjacent_sysfs_del(iter->dev, oldname,
8149                                           &iter->dev->adj_list.upper);
8150                 netdev_adjacent_sysfs_add(iter->dev, dev,
8151                                           &iter->dev->adj_list.upper);
8152         }
8153 }
8154
8155 void *netdev_lower_dev_get_private(struct net_device *dev,
8156                                    struct net_device *lower_dev)
8157 {
8158         struct netdev_adjacent *lower;
8159
8160         if (!lower_dev)
8161                 return NULL;
8162         lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
8163         if (!lower)
8164                 return NULL;
8165
8166         return lower->private;
8167 }
8168 EXPORT_SYMBOL(netdev_lower_dev_get_private);
8169
8170
8171 /**
8172  * netdev_lower_state_changed - Dispatch event about lower device state change
8173  * @lower_dev: device
8174  * @lower_state_info: state to dispatch
8175  *
8176  * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
8177  * The caller must hold the RTNL lock.
8178  */
8179 void netdev_lower_state_changed(struct net_device *lower_dev,
8180                                 void *lower_state_info)
8181 {
8182         struct netdev_notifier_changelowerstate_info changelowerstate_info = {
8183                 .info.dev = lower_dev,
8184         };
8185
8186         ASSERT_RTNL();
8187         changelowerstate_info.lower_state_info = lower_state_info;
8188         call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
8189                                       &changelowerstate_info.info);
8190 }
8191 EXPORT_SYMBOL(netdev_lower_state_changed);
8192
8193 static void dev_change_rx_flags(struct net_device *dev, int flags)
8194 {
8195         const struct net_device_ops *ops = dev->netdev_ops;
8196
8197         if (ops->ndo_change_rx_flags)
8198                 ops->ndo_change_rx_flags(dev, flags);
8199 }
8200
8201 static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
8202 {
8203         unsigned int old_flags = dev->flags;
8204         kuid_t uid;
8205         kgid_t gid;
8206
8207         ASSERT_RTNL();
8208
8209         dev->flags |= IFF_PROMISC;
8210         dev->promiscuity += inc;
8211         if (dev->promiscuity == 0) {
8212                 /*
8213                  * Avoid overflow.
8214                  * If inc causes overflow, untouch promisc and return error.
8215                  */
8216                 if (inc < 0)
8217                         dev->flags &= ~IFF_PROMISC;
8218                 else {
8219                         dev->promiscuity -= inc;
8220                         netdev_warn(dev, "promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n");
8221                         return -EOVERFLOW;
8222                 }
8223         }
8224         if (dev->flags != old_flags) {
8225                 pr_info("device %s %s promiscuous mode\n",
8226                         dev->name,
8227                         dev->flags & IFF_PROMISC ? "entered" : "left");
8228                 if (audit_enabled) {
8229                         current_uid_gid(&uid, &gid);
8230                         audit_log(audit_context(), GFP_ATOMIC,
8231                                   AUDIT_ANOM_PROMISCUOUS,
8232                                   "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
8233                                   dev->name, (dev->flags & IFF_PROMISC),
8234                                   (old_flags & IFF_PROMISC),
8235                                   from_kuid(&init_user_ns, audit_get_loginuid(current)),
8236                                   from_kuid(&init_user_ns, uid),
8237                                   from_kgid(&init_user_ns, gid),
8238                                   audit_get_sessionid(current));
8239                 }
8240
8241                 dev_change_rx_flags(dev, IFF_PROMISC);
8242         }
8243         if (notify)
8244                 __dev_notify_flags(dev, old_flags, IFF_PROMISC);
8245         return 0;
8246 }
8247
8248 /**
8249  *      dev_set_promiscuity     - update promiscuity count on a device
8250  *      @dev: device
8251  *      @inc: modifier
8252  *
8253  *      Add or remove promiscuity from a device. While the count in the device
8254  *      remains above zero the interface remains promiscuous. Once it hits zero
8255  *      the device reverts back to normal filtering operation. A negative inc
8256  *      value is used to drop promiscuity on the device.
8257  *      Return 0 if successful or a negative errno code on error.
8258  */
8259 int dev_set_promiscuity(struct net_device *dev, int inc)
8260 {
8261         unsigned int old_flags = dev->flags;
8262         int err;
8263
8264         err = __dev_set_promiscuity(dev, inc, true);
8265         if (err < 0)
8266                 return err;
8267         if (dev->flags != old_flags)
8268                 dev_set_rx_mode(dev);
8269         return err;
8270 }
8271 EXPORT_SYMBOL(dev_set_promiscuity);
8272
8273 static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
8274 {
8275         unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
8276
8277         ASSERT_RTNL();
8278
8279         dev->flags |= IFF_ALLMULTI;
8280         dev->allmulti += inc;
8281         if (dev->allmulti == 0) {
8282                 /*
8283                  * Avoid overflow.
8284                  * If inc causes overflow, untouch allmulti and return error.
8285                  */
8286                 if (inc < 0)
8287                         dev->flags &= ~IFF_ALLMULTI;
8288                 else {
8289                         dev->allmulti -= inc;
8290                         netdev_warn(dev, "allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n");
8291                         return -EOVERFLOW;
8292                 }
8293         }
8294         if (dev->flags ^ old_flags) {
8295                 dev_change_rx_flags(dev, IFF_ALLMULTI);
8296                 dev_set_rx_mode(dev);
8297                 if (notify)
8298                         __dev_notify_flags(dev, old_flags,
8299                                            dev->gflags ^ old_gflags);
8300         }
8301         return 0;
8302 }
8303
8304 /**
8305  *      dev_set_allmulti        - update allmulti count on a device
8306  *      @dev: device
8307  *      @inc: modifier
8308  *
8309  *      Add or remove reception of all multicast frames to a device. While the
8310  *      count in the device remains above zero the interface remains listening
8311  *      to all interfaces. Once it hits zero the device reverts back to normal
8312  *      filtering operation. A negative @inc value is used to drop the counter
8313  *      when releasing a resource needing all multicasts.
8314  *      Return 0 if successful or a negative errno code on error.
8315  */
8316
8317 int dev_set_allmulti(struct net_device *dev, int inc)
8318 {
8319         return __dev_set_allmulti(dev, inc, true);
8320 }
8321 EXPORT_SYMBOL(dev_set_allmulti);
8322
8323 /*
8324  *      Upload unicast and multicast address lists to device and
8325  *      configure RX filtering. When the device doesn't support unicast
8326  *      filtering it is put in promiscuous mode while unicast addresses
8327  *      are present.
8328  */
8329 void __dev_set_rx_mode(struct net_device *dev)
8330 {
8331         const struct net_device_ops *ops = dev->netdev_ops;
8332
8333         /* dev_open will call this function so the list will stay sane. */
8334         if (!(dev->flags&IFF_UP))
8335                 return;
8336
8337         if (!netif_device_present(dev))
8338                 return;
8339
8340         if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
8341                 /* Unicast addresses changes may only happen under the rtnl,
8342                  * therefore calling __dev_set_promiscuity here is safe.
8343                  */
8344                 if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
8345                         __dev_set_promiscuity(dev, 1, false);
8346                         dev->uc_promisc = true;
8347                 } else if (netdev_uc_empty(dev) && dev->uc_promisc) {
8348                         __dev_set_promiscuity(dev, -1, false);
8349                         dev->uc_promisc = false;
8350                 }
8351         }
8352
8353         if (ops->ndo_set_rx_mode)
8354                 ops->ndo_set_rx_mode(dev);
8355 }
8356
8357 void dev_set_rx_mode(struct net_device *dev)
8358 {
8359         netif_addr_lock_bh(dev);
8360         __dev_set_rx_mode(dev);
8361         netif_addr_unlock_bh(dev);
8362 }
8363
8364 /**
8365  *      dev_get_flags - get flags reported to userspace
8366  *      @dev: device
8367  *
8368  *      Get the combination of flag bits exported through APIs to userspace.
8369  */
8370 unsigned int dev_get_flags(const struct net_device *dev)
8371 {
8372         unsigned int flags;
8373
8374         flags = (dev->flags & ~(IFF_PROMISC |
8375                                 IFF_ALLMULTI |
8376                                 IFF_RUNNING |
8377                                 IFF_LOWER_UP |
8378                                 IFF_DORMANT)) |
8379                 (dev->gflags & (IFF_PROMISC |
8380                                 IFF_ALLMULTI));
8381
8382         if (netif_running(dev)) {
8383                 if (netif_oper_up(dev))
8384                         flags |= IFF_RUNNING;
8385                 if (netif_carrier_ok(dev))
8386                         flags |= IFF_LOWER_UP;
8387                 if (netif_dormant(dev))
8388                         flags |= IFF_DORMANT;
8389         }
8390
8391         return flags;
8392 }
8393 EXPORT_SYMBOL(dev_get_flags);
8394
8395 int __dev_change_flags(struct net_device *dev, unsigned int flags,
8396                        struct netlink_ext_ack *extack)
8397 {
8398         unsigned int old_flags = dev->flags;
8399         int ret;
8400
8401         ASSERT_RTNL();
8402
8403         /*
8404          *      Set the flags on our device.
8405          */
8406
8407         dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
8408                                IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
8409                                IFF_AUTOMEDIA)) |
8410                      (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
8411                                     IFF_ALLMULTI));
8412
8413         /*
8414          *      Load in the correct multicast list now the flags have changed.
8415          */
8416
8417         if ((old_flags ^ flags) & IFF_MULTICAST)
8418                 dev_change_rx_flags(dev, IFF_MULTICAST);
8419
8420         dev_set_rx_mode(dev);
8421
8422         /*
8423          *      Have we downed the interface. We handle IFF_UP ourselves
8424          *      according to user attempts to set it, rather than blindly
8425          *      setting it.
8426          */
8427
8428         ret = 0;
8429         if ((old_flags ^ flags) & IFF_UP) {
8430                 if (old_flags & IFF_UP)
8431                         __dev_close(dev);
8432                 else
8433                         ret = __dev_open(dev, extack);
8434         }
8435
8436         if ((flags ^ dev->gflags) & IFF_PROMISC) {
8437                 int inc = (flags & IFF_PROMISC) ? 1 : -1;
8438                 unsigned int old_flags = dev->flags;
8439
8440                 dev->gflags ^= IFF_PROMISC;
8441
8442                 if (__dev_set_promiscuity(dev, inc, false) >= 0)
8443                         if (dev->flags != old_flags)
8444                                 dev_set_rx_mode(dev);
8445         }
8446
8447         /* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
8448          * is important. Some (broken) drivers set IFF_PROMISC, when
8449          * IFF_ALLMULTI is requested not asking us and not reporting.
8450          */
8451         if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
8452                 int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
8453
8454                 dev->gflags ^= IFF_ALLMULTI;
8455                 __dev_set_allmulti(dev, inc, false);
8456         }
8457
8458         return ret;
8459 }
8460
8461 void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
8462                         unsigned int gchanges)
8463 {
8464         unsigned int changes = dev->flags ^ old_flags;
8465
8466         if (gchanges)
8467                 rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
8468
8469         if (changes & IFF_UP) {
8470                 if (dev->flags & IFF_UP)
8471                         call_netdevice_notifiers(NETDEV_UP, dev);
8472                 else
8473                         call_netdevice_notifiers(NETDEV_DOWN, dev);
8474         }
8475
8476         if (dev->flags & IFF_UP &&
8477             (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
8478                 struct netdev_notifier_change_info change_info = {
8479                         .info = {
8480                                 .dev = dev,
8481                         },
8482                         .flags_changed = changes,
8483                 };
8484
8485                 call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
8486         }
8487 }
8488
8489 /**
8490  *      dev_change_flags - change device settings
8491  *      @dev: device
8492  *      @flags: device state flags
8493  *      @extack: netlink extended ack
8494  *
8495  *      Change settings on device based state flags. The flags are
8496  *      in the userspace exported format.
8497  */
8498 int dev_change_flags(struct net_device *dev, unsigned int flags,
8499                      struct netlink_ext_ack *extack)
8500 {
8501         int ret;
8502         unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
8503
8504         ret = __dev_change_flags(dev, flags, extack);
8505         if (ret < 0)
8506                 return ret;
8507
8508         changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
8509         __dev_notify_flags(dev, old_flags, changes);
8510         return ret;
8511 }
8512 EXPORT_SYMBOL(dev_change_flags);
8513
8514 int __dev_set_mtu(struct net_device *dev, int new_mtu)
8515 {
8516         const struct net_device_ops *ops = dev->netdev_ops;
8517
8518         if (ops->ndo_change_mtu)
8519                 return ops->ndo_change_mtu(dev, new_mtu);
8520
8521         /* Pairs with all the lockless reads of dev->mtu in the stack */
8522         WRITE_ONCE(dev->mtu, new_mtu);
8523         return 0;
8524 }
8525 EXPORT_SYMBOL(__dev_set_mtu);
8526
8527 int dev_validate_mtu(struct net_device *dev, int new_mtu,
8528                      struct netlink_ext_ack *extack)
8529 {
8530         /* MTU must be positive, and in range */
8531         if (new_mtu < 0 || new_mtu < dev->min_mtu) {
8532                 NL_SET_ERR_MSG(extack, "mtu less than device minimum");
8533                 return -EINVAL;
8534         }
8535
8536         if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
8537                 NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
8538                 return -EINVAL;
8539         }
8540         return 0;
8541 }
8542
8543 /**
8544  *      dev_set_mtu_ext - Change maximum transfer unit
8545  *      @dev: device
8546  *      @new_mtu: new transfer unit
8547  *      @extack: netlink extended ack
8548  *
8549  *      Change the maximum transfer size of the network device.
8550  */
8551 int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
8552                     struct netlink_ext_ack *extack)
8553 {
8554         int err, orig_mtu;
8555
8556         if (new_mtu == dev->mtu)
8557                 return 0;
8558
8559         err = dev_validate_mtu(dev, new_mtu, extack);
8560         if (err)
8561                 return err;
8562
8563         if (!netif_device_present(dev))
8564                 return -ENODEV;
8565
8566         err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
8567         err = notifier_to_errno(err);
8568         if (err)
8569                 return err;
8570
8571         orig_mtu = dev->mtu;
8572         err = __dev_set_mtu(dev, new_mtu);
8573
8574         if (!err) {
8575                 err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8576                                                    orig_mtu);
8577                 err = notifier_to_errno(err);
8578                 if (err) {
8579                         /* setting mtu back and notifying everyone again,
8580                          * so that they have a chance to revert changes.
8581                          */
8582                         __dev_set_mtu(dev, orig_mtu);
8583                         call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
8584                                                      new_mtu);
8585                 }
8586         }
8587         return err;
8588 }
8589
8590 int dev_set_mtu(struct net_device *dev, int new_mtu)
8591 {
8592         struct netlink_ext_ack extack;
8593         int err;
8594
8595         memset(&extack, 0, sizeof(extack));
8596         err = dev_set_mtu_ext(dev, new_mtu, &extack);
8597         if (err && extack._msg)
8598                 net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
8599         return err;
8600 }
8601 EXPORT_SYMBOL(dev_set_mtu);
8602
8603 /**
8604  *      dev_change_tx_queue_len - Change TX queue length of a netdevice
8605  *      @dev: device
8606  *      @new_len: new tx queue length
8607  */
8608 int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
8609 {
8610         unsigned int orig_len = dev->tx_queue_len;
8611         int res;
8612
8613         if (new_len != (unsigned int)new_len)
8614                 return -ERANGE;
8615
8616         if (new_len != orig_len) {
8617                 dev->tx_queue_len = new_len;
8618                 res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
8619                 res = notifier_to_errno(res);
8620                 if (res)
8621                         goto err_rollback;
8622                 res = dev_qdisc_change_tx_queue_len(dev);
8623                 if (res)
8624                         goto err_rollback;
8625         }
8626
8627         return 0;
8628
8629 err_rollback:
8630         netdev_err(dev, "refused to change device tx_queue_len\n");
8631         dev->tx_queue_len = orig_len;
8632         return res;
8633 }
8634
8635 /**
8636  *      dev_set_group - Change group this device belongs to
8637  *      @dev: device
8638  *      @new_group: group this device should belong to
8639  */
8640 void dev_set_group(struct net_device *dev, int new_group)
8641 {
8642         dev->group = new_group;
8643 }
8644 EXPORT_SYMBOL(dev_set_group);
8645
8646 /**
8647  *      dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
8648  *      @dev: device
8649  *      @addr: new address
8650  *      @extack: netlink extended ack
8651  */
8652 int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
8653                               struct netlink_ext_ack *extack)
8654 {
8655         struct netdev_notifier_pre_changeaddr_info info = {
8656                 .info.dev = dev,
8657                 .info.extack = extack,
8658                 .dev_addr = addr,
8659         };
8660         int rc;
8661
8662         rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
8663         return notifier_to_errno(rc);
8664 }
8665 EXPORT_SYMBOL(dev_pre_changeaddr_notify);
8666
8667 /**
8668  *      dev_set_mac_address - Change Media Access Control Address
8669  *      @dev: device
8670  *      @sa: new address
8671  *      @extack: netlink extended ack
8672  *
8673  *      Change the hardware (MAC) address of the device
8674  */
8675 int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
8676                         struct netlink_ext_ack *extack)
8677 {
8678         const struct net_device_ops *ops = dev->netdev_ops;
8679         int err;
8680
8681         if (!ops->ndo_set_mac_address)
8682                 return -EOPNOTSUPP;
8683         if (sa->sa_family != dev->type)
8684                 return -EINVAL;
8685         if (!netif_device_present(dev))
8686                 return -ENODEV;
8687         err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
8688         if (err)
8689                 return err;
8690         err = ops->ndo_set_mac_address(dev, sa);
8691         if (err)
8692                 return err;
8693         dev->addr_assign_type = NET_ADDR_SET;
8694         call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
8695         add_device_randomness(dev->dev_addr, dev->addr_len);
8696         return 0;
8697 }
8698 EXPORT_SYMBOL(dev_set_mac_address);
8699
8700 static DECLARE_RWSEM(dev_addr_sem);
8701
8702 int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
8703                              struct netlink_ext_ack *extack)
8704 {
8705         int ret;
8706
8707         down_write(&dev_addr_sem);
8708         ret = dev_set_mac_address(dev, sa, extack);
8709         up_write(&dev_addr_sem);
8710         return ret;
8711 }
8712 EXPORT_SYMBOL(dev_set_mac_address_user);
8713
8714 int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
8715 {
8716         size_t size = sizeof(sa->sa_data);
8717         struct net_device *dev;
8718         int ret = 0;
8719
8720         down_read(&dev_addr_sem);
8721         rcu_read_lock();
8722
8723         dev = dev_get_by_name_rcu(net, dev_name);
8724         if (!dev) {
8725                 ret = -ENODEV;
8726                 goto unlock;
8727         }
8728         if (!dev->addr_len)
8729                 memset(sa->sa_data, 0, size);
8730         else
8731                 memcpy(sa->sa_data, dev->dev_addr,
8732                        min_t(size_t, size, dev->addr_len));
8733         sa->sa_family = dev->type;
8734
8735 unlock:
8736         rcu_read_unlock();
8737         up_read(&dev_addr_sem);
8738         return ret;
8739 }
8740 EXPORT_SYMBOL(dev_get_mac_address);
8741
8742 /**
8743  *      dev_change_carrier - Change device carrier
8744  *      @dev: device
8745  *      @new_carrier: new value
8746  *
8747  *      Change device carrier
8748  */
8749 int dev_change_carrier(struct net_device *dev, bool new_carrier)
8750 {
8751         const struct net_device_ops *ops = dev->netdev_ops;
8752
8753         if (!ops->ndo_change_carrier)
8754                 return -EOPNOTSUPP;
8755         if (!netif_device_present(dev))
8756                 return -ENODEV;
8757         return ops->ndo_change_carrier(dev, new_carrier);
8758 }
8759 EXPORT_SYMBOL(dev_change_carrier);
8760
8761 /**
8762  *      dev_get_phys_port_id - Get device physical port ID
8763  *      @dev: device
8764  *      @ppid: port ID
8765  *
8766  *      Get device physical port ID
8767  */
8768 int dev_get_phys_port_id(struct net_device *dev,
8769                          struct netdev_phys_item_id *ppid)
8770 {
8771         const struct net_device_ops *ops = dev->netdev_ops;
8772
8773         if (!ops->ndo_get_phys_port_id)
8774                 return -EOPNOTSUPP;
8775         return ops->ndo_get_phys_port_id(dev, ppid);
8776 }
8777 EXPORT_SYMBOL(dev_get_phys_port_id);
8778
8779 /**
8780  *      dev_get_phys_port_name - Get device physical port name
8781  *      @dev: device
8782  *      @name: port name
8783  *      @len: limit of bytes to copy to name
8784  *
8785  *      Get device physical port name
8786  */
8787 int dev_get_phys_port_name(struct net_device *dev,
8788                            char *name, size_t len)
8789 {
8790         const struct net_device_ops *ops = dev->netdev_ops;
8791         int err;
8792
8793         if (ops->ndo_get_phys_port_name) {
8794                 err = ops->ndo_get_phys_port_name(dev, name, len);
8795                 if (err != -EOPNOTSUPP)
8796                         return err;
8797         }
8798         return devlink_compat_phys_port_name_get(dev, name, len);
8799 }
8800 EXPORT_SYMBOL(dev_get_phys_port_name);
8801
8802 /**
8803  *      dev_get_port_parent_id - Get the device's port parent identifier
8804  *      @dev: network device
8805  *      @ppid: pointer to a storage for the port's parent identifier
8806  *      @recurse: allow/disallow recursion to lower devices
8807  *
8808  *      Get the devices's port parent identifier
8809  */
8810 int dev_get_port_parent_id(struct net_device *dev,
8811                            struct netdev_phys_item_id *ppid,
8812                            bool recurse)
8813 {
8814         const struct net_device_ops *ops = dev->netdev_ops;
8815         struct netdev_phys_item_id first = { };
8816         struct net_device *lower_dev;
8817         struct list_head *iter;
8818         int err;
8819
8820         if (ops->ndo_get_port_parent_id) {
8821                 err = ops->ndo_get_port_parent_id(dev, ppid);
8822                 if (err != -EOPNOTSUPP)
8823                         return err;
8824         }
8825
8826         err = devlink_compat_switch_id_get(dev, ppid);
8827         if (!recurse || err != -EOPNOTSUPP)
8828                 return err;
8829
8830         netdev_for_each_lower_dev(dev, lower_dev, iter) {
8831                 err = dev_get_port_parent_id(lower_dev, ppid, true);
8832                 if (err)
8833                         break;
8834                 if (!first.id_len)
8835                         first = *ppid;
8836                 else if (memcmp(&first, ppid, sizeof(*ppid)))
8837                         return -EOPNOTSUPP;
8838         }
8839
8840         return err;
8841 }
8842 EXPORT_SYMBOL(dev_get_port_parent_id);
8843
8844 /**
8845  *      netdev_port_same_parent_id - Indicate if two network devices have
8846  *      the same port parent identifier
8847  *      @a: first network device
8848  *      @b: second network device
8849  */
8850 bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
8851 {
8852         struct netdev_phys_item_id a_id = { };
8853         struct netdev_phys_item_id b_id = { };
8854
8855         if (dev_get_port_parent_id(a, &a_id, true) ||
8856             dev_get_port_parent_id(b, &b_id, true))
8857                 return false;
8858
8859         return netdev_phys_item_id_same(&a_id, &b_id);
8860 }
8861 EXPORT_SYMBOL(netdev_port_same_parent_id);
8862
8863 /**
8864  *      dev_change_proto_down - set carrier according to proto_down.
8865  *
8866  *      @dev: device
8867  *      @proto_down: new value
8868  */
8869 int dev_change_proto_down(struct net_device *dev, bool proto_down)
8870 {
8871         if (!(dev->priv_flags & IFF_CHANGE_PROTO_DOWN))
8872                 return -EOPNOTSUPP;
8873         if (!netif_device_present(dev))
8874                 return -ENODEV;
8875         if (proto_down)
8876                 netif_carrier_off(dev);
8877         else
8878                 netif_carrier_on(dev);
8879         dev->proto_down = proto_down;
8880         return 0;
8881 }
8882 EXPORT_SYMBOL(dev_change_proto_down);
8883
8884 /**
8885  *      dev_change_proto_down_reason - proto down reason
8886  *
8887  *      @dev: device
8888  *      @mask: proto down mask
8889  *      @value: proto down value
8890  */
8891 void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
8892                                   u32 value)
8893 {
8894         int b;
8895
8896         if (!mask) {
8897                 dev->proto_down_reason = value;
8898         } else {
8899                 for_each_set_bit(b, &mask, 32) {
8900                         if (value & (1 << b))
8901                                 dev->proto_down_reason |= BIT(b);
8902                         else
8903                                 dev->proto_down_reason &= ~BIT(b);
8904                 }
8905         }
8906 }
8907 EXPORT_SYMBOL(dev_change_proto_down_reason);
8908
8909 struct bpf_xdp_link {
8910         struct bpf_link link;
8911         struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
8912         int flags;
8913 };
8914
8915 static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
8916 {
8917         if (flags & XDP_FLAGS_HW_MODE)
8918                 return XDP_MODE_HW;
8919         if (flags & XDP_FLAGS_DRV_MODE)
8920                 return XDP_MODE_DRV;
8921         if (flags & XDP_FLAGS_SKB_MODE)
8922                 return XDP_MODE_SKB;
8923         return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
8924 }
8925
8926 static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
8927 {
8928         switch (mode) {
8929         case XDP_MODE_SKB:
8930                 return generic_xdp_install;
8931         case XDP_MODE_DRV:
8932         case XDP_MODE_HW:
8933                 return dev->netdev_ops->ndo_bpf;
8934         default:
8935                 return NULL;
8936         }
8937 }
8938
8939 static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
8940                                          enum bpf_xdp_mode mode)
8941 {
8942         return dev->xdp_state[mode].link;
8943 }
8944
8945 static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
8946                                      enum bpf_xdp_mode mode)
8947 {
8948         struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
8949
8950         if (link)
8951                 return link->link.prog;
8952         return dev->xdp_state[mode].prog;
8953 }
8954
8955 u8 dev_xdp_prog_count(struct net_device *dev)
8956 {
8957         u8 count = 0;
8958         int i;
8959
8960         for (i = 0; i < __MAX_XDP_MODE; i++)
8961                 if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
8962                         count++;
8963         return count;
8964 }
8965 EXPORT_SYMBOL_GPL(dev_xdp_prog_count);
8966
8967 u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
8968 {
8969         struct bpf_prog *prog = dev_xdp_prog(dev, mode);
8970
8971         return prog ? prog->aux->id : 0;
8972 }
8973
8974 static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
8975                              struct bpf_xdp_link *link)
8976 {
8977         dev->xdp_state[mode].link = link;
8978         dev->xdp_state[mode].prog = NULL;
8979 }
8980
8981 static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
8982                              struct bpf_prog *prog)
8983 {
8984         dev->xdp_state[mode].link = NULL;
8985         dev->xdp_state[mode].prog = prog;
8986 }
8987
8988 static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
8989                            bpf_op_t bpf_op, struct netlink_ext_ack *extack,
8990                            u32 flags, struct bpf_prog *prog)
8991 {
8992         struct netdev_bpf xdp;
8993         int err;
8994
8995         memset(&xdp, 0, sizeof(xdp));
8996         xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
8997         xdp.extack = extack;
8998         xdp.flags = flags;
8999         xdp.prog = prog;
9000
9001         /* Drivers assume refcnt is already incremented (i.e, prog pointer is
9002          * "moved" into driver), so they don't increment it on their own, but
9003          * they do decrement refcnt when program is detached or replaced.
9004          * Given net_device also owns link/prog, we need to bump refcnt here
9005          * to prevent drivers from underflowing it.
9006          */
9007         if (prog)
9008                 bpf_prog_inc(prog);
9009         err = bpf_op(dev, &xdp);
9010         if (err) {
9011                 if (prog)
9012                         bpf_prog_put(prog);
9013                 return err;
9014         }
9015
9016         if (mode != XDP_MODE_HW)
9017                 bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
9018
9019         return 0;
9020 }
9021
9022 static void dev_xdp_uninstall(struct net_device *dev)
9023 {
9024         struct bpf_xdp_link *link;
9025         struct bpf_prog *prog;
9026         enum bpf_xdp_mode mode;
9027         bpf_op_t bpf_op;
9028
9029         ASSERT_RTNL();
9030
9031         for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
9032                 prog = dev_xdp_prog(dev, mode);
9033                 if (!prog)
9034                         continue;
9035
9036                 bpf_op = dev_xdp_bpf_op(dev, mode);
9037                 if (!bpf_op)
9038                         continue;
9039
9040                 WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9041
9042                 /* auto-detach link from net device */
9043                 link = dev_xdp_link(dev, mode);
9044                 if (link)
9045                         link->dev = NULL;
9046                 else
9047                         bpf_prog_put(prog);
9048
9049                 dev_xdp_set_link(dev, mode, NULL);
9050         }
9051 }
9052
9053 static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
9054                           struct bpf_xdp_link *link, struct bpf_prog *new_prog,
9055                           struct bpf_prog *old_prog, u32 flags)
9056 {
9057         unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
9058         struct bpf_prog *cur_prog;
9059         struct net_device *upper;
9060         struct list_head *iter;
9061         enum bpf_xdp_mode mode;
9062         bpf_op_t bpf_op;
9063         int err;
9064
9065         ASSERT_RTNL();
9066
9067         /* either link or prog attachment, never both */
9068         if (link && (new_prog || old_prog))
9069                 return -EINVAL;
9070         /* link supports only XDP mode flags */
9071         if (link && (flags & ~XDP_FLAGS_MODES)) {
9072                 NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
9073                 return -EINVAL;
9074         }
9075         /* just one XDP mode bit should be set, zero defaults to drv/skb mode */
9076         if (num_modes > 1) {
9077                 NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
9078                 return -EINVAL;
9079         }
9080         /* avoid ambiguity if offload + drv/skb mode progs are both loaded */
9081         if (!num_modes && dev_xdp_prog_count(dev) > 1) {
9082                 NL_SET_ERR_MSG(extack,
9083                                "More than one program loaded, unset mode is ambiguous");
9084                 return -EINVAL;
9085         }
9086         /* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
9087         if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
9088                 NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
9089                 return -EINVAL;
9090         }
9091
9092         mode = dev_xdp_mode(dev, flags);
9093         /* can't replace attached link */
9094         if (dev_xdp_link(dev, mode)) {
9095                 NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
9096                 return -EBUSY;
9097         }
9098
9099         /* don't allow if an upper device already has a program */
9100         netdev_for_each_upper_dev_rcu(dev, upper, iter) {
9101                 if (dev_xdp_prog_count(upper) > 0) {
9102                         NL_SET_ERR_MSG(extack, "Cannot attach when an upper device already has a program");
9103                         return -EEXIST;
9104                 }
9105         }
9106
9107         cur_prog = dev_xdp_prog(dev, mode);
9108         /* can't replace attached prog with link */
9109         if (link && cur_prog) {
9110                 NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
9111                 return -EBUSY;
9112         }
9113         if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
9114                 NL_SET_ERR_MSG(extack, "Active program does not match expected");
9115                 return -EEXIST;
9116         }
9117
9118         /* put effective new program into new_prog */
9119         if (link)
9120                 new_prog = link->link.prog;
9121
9122         if (new_prog) {
9123                 bool offload = mode == XDP_MODE_HW;
9124                 enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
9125                                                ? XDP_MODE_DRV : XDP_MODE_SKB;
9126
9127                 if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
9128                         NL_SET_ERR_MSG(extack, "XDP program already attached");
9129                         return -EBUSY;
9130                 }
9131                 if (!offload && dev_xdp_prog(dev, other_mode)) {
9132                         NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
9133                         return -EEXIST;
9134                 }
9135                 if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
9136                         NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
9137                         return -EINVAL;
9138                 }
9139                 if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
9140                         NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
9141                         return -EINVAL;
9142                 }
9143                 if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
9144                         NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
9145                         return -EINVAL;
9146                 }
9147         }
9148
9149         /* don't call drivers if the effective program didn't change */
9150         if (new_prog != cur_prog) {
9151                 bpf_op = dev_xdp_bpf_op(dev, mode);
9152                 if (!bpf_op) {
9153                         NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
9154                         return -EOPNOTSUPP;
9155                 }
9156
9157                 err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
9158                 if (err)
9159                         return err;
9160         }
9161
9162         if (link)
9163                 dev_xdp_set_link(dev, mode, link);
9164         else
9165                 dev_xdp_set_prog(dev, mode, new_prog);
9166         if (cur_prog)
9167                 bpf_prog_put(cur_prog);
9168
9169         return 0;
9170 }
9171
9172 static int dev_xdp_attach_link(struct net_device *dev,
9173                                struct netlink_ext_ack *extack,
9174                                struct bpf_xdp_link *link)
9175 {
9176         return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
9177 }
9178
9179 static int dev_xdp_detach_link(struct net_device *dev,
9180                                struct netlink_ext_ack *extack,
9181                                struct bpf_xdp_link *link)
9182 {
9183         enum bpf_xdp_mode mode;
9184         bpf_op_t bpf_op;
9185
9186         ASSERT_RTNL();
9187
9188         mode = dev_xdp_mode(dev, link->flags);
9189         if (dev_xdp_link(dev, mode) != link)
9190                 return -EINVAL;
9191
9192         bpf_op = dev_xdp_bpf_op(dev, mode);
9193         WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
9194         dev_xdp_set_link(dev, mode, NULL);
9195         return 0;
9196 }
9197
9198 static void bpf_xdp_link_release(struct bpf_link *link)
9199 {
9200         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9201
9202         rtnl_lock();
9203
9204         /* if racing with net_device's tear down, xdp_link->dev might be
9205          * already NULL, in which case link was already auto-detached
9206          */
9207         if (xdp_link->dev) {
9208                 WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
9209                 xdp_link->dev = NULL;
9210         }
9211
9212         rtnl_unlock();
9213 }
9214
9215 static int bpf_xdp_link_detach(struct bpf_link *link)
9216 {
9217         bpf_xdp_link_release(link);
9218         return 0;
9219 }
9220
9221 static void bpf_xdp_link_dealloc(struct bpf_link *link)
9222 {
9223         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9224
9225         kfree(xdp_link);
9226 }
9227
9228 static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
9229                                      struct seq_file *seq)
9230 {
9231         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9232         u32 ifindex = 0;
9233
9234         rtnl_lock();
9235         if (xdp_link->dev)
9236                 ifindex = xdp_link->dev->ifindex;
9237         rtnl_unlock();
9238
9239         seq_printf(seq, "ifindex:\t%u\n", ifindex);
9240 }
9241
9242 static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
9243                                        struct bpf_link_info *info)
9244 {
9245         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9246         u32 ifindex = 0;
9247
9248         rtnl_lock();
9249         if (xdp_link->dev)
9250                 ifindex = xdp_link->dev->ifindex;
9251         rtnl_unlock();
9252
9253         info->xdp.ifindex = ifindex;
9254         return 0;
9255 }
9256
9257 static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
9258                                struct bpf_prog *old_prog)
9259 {
9260         struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
9261         enum bpf_xdp_mode mode;
9262         bpf_op_t bpf_op;
9263         int err = 0;
9264
9265         rtnl_lock();
9266
9267         /* link might have been auto-released already, so fail */
9268         if (!xdp_link->dev) {
9269                 err = -ENOLINK;
9270                 goto out_unlock;
9271         }
9272
9273         if (old_prog && link->prog != old_prog) {
9274                 err = -EPERM;
9275                 goto out_unlock;
9276         }
9277         old_prog = link->prog;
9278         if (old_prog->type != new_prog->type ||
9279             old_prog->expected_attach_type != new_prog->expected_attach_type) {
9280                 err = -EINVAL;
9281                 goto out_unlock;
9282         }
9283
9284         if (old_prog == new_prog) {
9285                 /* no-op, don't disturb drivers */
9286                 bpf_prog_put(new_prog);
9287                 goto out_unlock;
9288         }
9289
9290         mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
9291         bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
9292         err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
9293                               xdp_link->flags, new_prog);
9294         if (err)
9295                 goto out_unlock;
9296
9297         old_prog = xchg(&link->prog, new_prog);
9298         bpf_prog_put(old_prog);
9299
9300 out_unlock:
9301         rtnl_unlock();
9302         return err;
9303 }
9304
9305 static const struct bpf_link_ops bpf_xdp_link_lops = {
9306         .release = bpf_xdp_link_release,
9307         .dealloc = bpf_xdp_link_dealloc,
9308         .detach = bpf_xdp_link_detach,
9309         .show_fdinfo = bpf_xdp_link_show_fdinfo,
9310         .fill_link_info = bpf_xdp_link_fill_link_info,
9311         .update_prog = bpf_xdp_link_update,
9312 };
9313
9314 int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
9315 {
9316         struct net *net = current->nsproxy->net_ns;
9317         struct bpf_link_primer link_primer;
9318         struct bpf_xdp_link *link;
9319         struct net_device *dev;
9320         int err, fd;
9321
9322         rtnl_lock();
9323         dev = dev_get_by_index(net, attr->link_create.target_ifindex);
9324         if (!dev) {
9325                 rtnl_unlock();
9326                 return -EINVAL;
9327         }
9328
9329         link = kzalloc(sizeof(*link), GFP_USER);
9330         if (!link) {
9331                 err = -ENOMEM;
9332                 goto unlock;
9333         }
9334
9335         bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
9336         link->dev = dev;
9337         link->flags = attr->link_create.flags;
9338
9339         err = bpf_link_prime(&link->link, &link_primer);
9340         if (err) {
9341                 kfree(link);
9342                 goto unlock;
9343         }
9344
9345         err = dev_xdp_attach_link(dev, NULL, link);
9346         rtnl_unlock();
9347
9348         if (err) {
9349                 link->dev = NULL;
9350                 bpf_link_cleanup(&link_primer);
9351                 goto out_put_dev;
9352         }
9353
9354         fd = bpf_link_settle(&link_primer);
9355         /* link itself doesn't hold dev's refcnt to not complicate shutdown */
9356         dev_put(dev);
9357         return fd;
9358
9359 unlock:
9360         rtnl_unlock();
9361
9362 out_put_dev:
9363         dev_put(dev);
9364         return err;
9365 }
9366
9367 /**
9368  *      dev_change_xdp_fd - set or clear a bpf program for a device rx path
9369  *      @dev: device
9370  *      @extack: netlink extended ack
9371  *      @fd: new program fd or negative value to clear
9372  *      @expected_fd: old program fd that userspace expects to replace or clear
9373  *      @flags: xdp-related flags
9374  *
9375  *      Set or clear a bpf program for a device
9376  */
9377 int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
9378                       int fd, int expected_fd, u32 flags)
9379 {
9380         enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
9381         struct bpf_prog *new_prog = NULL, *old_prog = NULL;
9382         int err;
9383
9384         ASSERT_RTNL();
9385
9386         if (fd >= 0) {
9387                 new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
9388                                                  mode != XDP_MODE_SKB);
9389                 if (IS_ERR(new_prog))
9390                         return PTR_ERR(new_prog);
9391         }
9392
9393         if (expected_fd >= 0) {
9394                 old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
9395                                                  mode != XDP_MODE_SKB);
9396                 if (IS_ERR(old_prog)) {
9397                         err = PTR_ERR(old_prog);
9398                         old_prog = NULL;
9399                         goto err_out;
9400                 }
9401         }
9402
9403         err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
9404
9405 err_out:
9406         if (err && new_prog)
9407                 bpf_prog_put(new_prog);
9408         if (old_prog)
9409                 bpf_prog_put(old_prog);
9410         return err;
9411 }
9412
9413 /**
9414  *      dev_new_index   -       allocate an ifindex
9415  *      @net: the applicable net namespace
9416  *
9417  *      Returns a suitable unique value for a new device interface
9418  *      number.  The caller must hold the rtnl semaphore or the
9419  *      dev_base_lock to be sure it remains unique.
9420  */
9421 static int dev_new_index(struct net *net)
9422 {
9423         int ifindex = net->ifindex;
9424
9425         for (;;) {
9426                 if (++ifindex <= 0)
9427                         ifindex = 1;
9428                 if (!__dev_get_by_index(net, ifindex))
9429                         return net->ifindex = ifindex;
9430         }
9431 }
9432
9433 /* Delayed registration/unregisteration */
9434 static LIST_HEAD(net_todo_list);
9435 DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
9436
9437 static void net_set_todo(struct net_device *dev)
9438 {
9439         list_add_tail(&dev->todo_list, &net_todo_list);
9440         atomic_inc(&dev_net(dev)->dev_unreg_count);
9441 }
9442
9443 static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
9444         struct net_device *upper, netdev_features_t features)
9445 {
9446         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9447         netdev_features_t feature;
9448         int feature_bit;
9449
9450         for_each_netdev_feature(upper_disables, feature_bit) {
9451                 feature = __NETIF_F_BIT(feature_bit);
9452                 if (!(upper->wanted_features & feature)
9453                     && (features & feature)) {
9454                         netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
9455                                    &feature, upper->name);
9456                         features &= ~feature;
9457                 }
9458         }
9459
9460         return features;
9461 }
9462
9463 static void netdev_sync_lower_features(struct net_device *upper,
9464         struct net_device *lower, netdev_features_t features)
9465 {
9466         netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
9467         netdev_features_t feature;
9468         int feature_bit;
9469
9470         for_each_netdev_feature(upper_disables, feature_bit) {
9471                 feature = __NETIF_F_BIT(feature_bit);
9472                 if (!(features & feature) && (lower->features & feature)) {
9473                         netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
9474                                    &feature, lower->name);
9475                         lower->wanted_features &= ~feature;
9476                         __netdev_update_features(lower);
9477
9478                         if (unlikely(lower->features & feature))
9479                                 netdev_WARN(upper, "failed to disable %pNF on %s!\n",
9480                                             &feature, lower->name);
9481                         else
9482                                 netdev_features_change(lower);
9483                 }
9484         }
9485 }
9486
9487 static netdev_features_t netdev_fix_features(struct net_device *dev,
9488         netdev_features_t features)
9489 {
9490         /* Fix illegal checksum combinations */
9491         if ((features & NETIF_F_HW_CSUM) &&
9492             (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
9493                 netdev_warn(dev, "mixed HW and IP checksum settings.\n");
9494                 features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
9495         }
9496
9497         /* TSO requires that SG is present as well. */
9498         if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
9499                 netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
9500                 features &= ~NETIF_F_ALL_TSO;
9501         }
9502
9503         if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
9504                                         !(features & NETIF_F_IP_CSUM)) {
9505                 netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
9506                 features &= ~NETIF_F_TSO;
9507                 features &= ~NETIF_F_TSO_ECN;
9508         }
9509
9510         if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
9511                                          !(features & NETIF_F_IPV6_CSUM)) {
9512                 netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
9513                 features &= ~NETIF_F_TSO6;
9514         }
9515
9516         /* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
9517         if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
9518                 features &= ~NETIF_F_TSO_MANGLEID;
9519
9520         /* TSO ECN requires that TSO is present as well. */
9521         if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
9522                 features &= ~NETIF_F_TSO_ECN;
9523
9524         /* Software GSO depends on SG. */
9525         if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
9526                 netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
9527                 features &= ~NETIF_F_GSO;
9528         }
9529
9530         /* GSO partial features require GSO partial be set */
9531         if ((features & dev->gso_partial_features) &&
9532             !(features & NETIF_F_GSO_PARTIAL)) {
9533                 netdev_dbg(dev,
9534                            "Dropping partially supported GSO features since no GSO partial.\n");
9535                 features &= ~dev->gso_partial_features;
9536         }
9537
9538         if (!(features & NETIF_F_RXCSUM)) {
9539                 /* NETIF_F_GRO_HW implies doing RXCSUM since every packet
9540                  * successfully merged by hardware must also have the
9541                  * checksum verified by hardware.  If the user does not
9542                  * want to enable RXCSUM, logically, we should disable GRO_HW.
9543                  */
9544                 if (features & NETIF_F_GRO_HW) {
9545                         netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
9546                         features &= ~NETIF_F_GRO_HW;
9547                 }
9548         }
9549
9550         /* LRO/HW-GRO features cannot be combined with RX-FCS */
9551         if (features & NETIF_F_RXFCS) {
9552                 if (features & NETIF_F_LRO) {
9553                         netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
9554                         features &= ~NETIF_F_LRO;
9555                 }
9556
9557                 if (features & NETIF_F_GRO_HW) {
9558                         netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
9559                         features &= ~NETIF_F_GRO_HW;
9560                 }
9561         }
9562
9563         if ((features & NETIF_F_GRO_HW) && (features & NETIF_F_LRO)) {
9564                 netdev_dbg(dev, "Dropping LRO feature since HW-GRO is requested.\n");
9565                 features &= ~NETIF_F_LRO;
9566         }
9567
9568         if (features & NETIF_F_HW_TLS_TX) {
9569                 bool ip_csum = (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) ==
9570                         (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
9571                 bool hw_csum = features & NETIF_F_HW_CSUM;
9572
9573                 if (!ip_csum && !hw_csum) {
9574                         netdev_dbg(dev, "Dropping TLS TX HW offload feature since no CSUM feature.\n");
9575                         features &= ~NETIF_F_HW_TLS_TX;
9576                 }
9577         }
9578
9579         if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
9580                 netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
9581                 features &= ~NETIF_F_HW_TLS_RX;
9582         }
9583
9584         return features;
9585 }
9586
9587 int __netdev_update_features(struct net_device *dev)
9588 {
9589         struct net_device *upper, *lower;
9590         netdev_features_t features;
9591         struct list_head *iter;
9592         int err = -1;
9593
9594         ASSERT_RTNL();
9595
9596         features = netdev_get_wanted_features(dev);
9597
9598         if (dev->netdev_ops->ndo_fix_features)
9599                 features = dev->netdev_ops->ndo_fix_features(dev, features);
9600
9601         /* driver might be less strict about feature dependencies */
9602         features = netdev_fix_features(dev, features);
9603
9604         /* some features can't be enabled if they're off on an upper device */
9605         netdev_for_each_upper_dev_rcu(dev, upper, iter)
9606                 features = netdev_sync_upper_features(dev, upper, features);
9607
9608         if (dev->features == features)
9609                 goto sync_lower;
9610
9611         netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
9612                 &dev->features, &features);
9613
9614         if (dev->netdev_ops->ndo_set_features)
9615                 err = dev->netdev_ops->ndo_set_features(dev, features);
9616         else
9617                 err = 0;
9618
9619         if (unlikely(err < 0)) {
9620                 netdev_err(dev,
9621                         "set_features() failed (%d); wanted %pNF, left %pNF\n",
9622                         err, &features, &dev->features);
9623                 /* return non-0 since some features might have changed and
9624                  * it's better to fire a spurious notification than miss it
9625                  */
9626                 return -1;
9627         }
9628
9629 sync_lower:
9630         /* some features must be disabled on lower devices when disabled
9631          * on an upper device (think: bonding master or bridge)
9632          */
9633         netdev_for_each_lower_dev(dev, lower, iter)
9634                 netdev_sync_lower_features(dev, lower, features);
9635
9636         if (!err) {
9637                 netdev_features_t diff = features ^ dev->features;
9638
9639                 if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
9640                         /* udp_tunnel_{get,drop}_rx_info both need
9641                          * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
9642                          * device, or they won't do anything.
9643                          * Thus we need to update dev->features
9644                          * *before* calling udp_tunnel_get_rx_info,
9645                          * but *after* calling udp_tunnel_drop_rx_info.
9646                          */
9647                         if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
9648                                 dev->features = features;
9649                                 udp_tunnel_get_rx_info(dev);
9650                         } else {
9651                                 udp_tunnel_drop_rx_info(dev);
9652                         }
9653                 }
9654
9655                 if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
9656                         if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
9657                                 dev->features = features;
9658                                 err |= vlan_get_rx_ctag_filter_info(dev);
9659                         } else {
9660                                 vlan_drop_rx_ctag_filter_info(dev);
9661                         }
9662                 }
9663
9664                 if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
9665                         if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
9666                                 dev->features = features;
9667                                 err |= vlan_get_rx_stag_filter_info(dev);
9668                         } else {
9669                                 vlan_drop_rx_stag_filter_info(dev);
9670                         }
9671                 }
9672
9673                 dev->features = features;
9674         }
9675
9676         return err < 0 ? 0 : 1;
9677 }
9678
9679 /**
9680  *      netdev_update_features - recalculate device features
9681  *      @dev: the device to check
9682  *
9683  *      Recalculate dev->features set and send notifications if it
9684  *      has changed. Should be called after driver or hardware dependent
9685  *      conditions might have changed that influence the features.
9686  */
9687 void netdev_update_features(struct net_device *dev)
9688 {
9689         if (__netdev_update_features(dev))
9690                 netdev_features_change(dev);
9691 }
9692 EXPORT_SYMBOL(netdev_update_features);
9693
9694 /**
9695  *      netdev_change_features - recalculate device features
9696  *      @dev: the device to check
9697  *
9698  *      Recalculate dev->features set and send notifications even
9699  *      if they have not changed. Should be called instead of
9700  *      netdev_update_features() if also dev->vlan_features might
9701  *      have changed to allow the changes to be propagated to stacked
9702  *      VLAN devices.
9703  */
9704 void netdev_change_features(struct net_device *dev)
9705 {
9706         __netdev_update_features(dev);
9707         netdev_features_change(dev);
9708 }
9709 EXPORT_SYMBOL(netdev_change_features);
9710
9711 /**
9712  *      netif_stacked_transfer_operstate -      transfer operstate
9713  *      @rootdev: the root or lower level device to transfer state from
9714  *      @dev: the device to transfer operstate to
9715  *
9716  *      Transfer operational state from root to device. This is normally
9717  *      called when a stacking relationship exists between the root
9718  *      device and the device(a leaf device).
9719  */
9720 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
9721                                         struct net_device *dev)
9722 {
9723         if (rootdev->operstate == IF_OPER_DORMANT)
9724                 netif_dormant_on(dev);
9725         else
9726                 netif_dormant_off(dev);
9727
9728         if (rootdev->operstate == IF_OPER_TESTING)
9729                 netif_testing_on(dev);
9730         else
9731                 netif_testing_off(dev);
9732
9733         if (netif_carrier_ok(rootdev))
9734                 netif_carrier_on(dev);
9735         else
9736                 netif_carrier_off(dev);
9737 }
9738 EXPORT_SYMBOL(netif_stacked_transfer_operstate);
9739
9740 static int netif_alloc_rx_queues(struct net_device *dev)
9741 {
9742         unsigned int i, count = dev->num_rx_queues;
9743         struct netdev_rx_queue *rx;
9744         size_t sz = count * sizeof(*rx);
9745         int err = 0;
9746
9747         BUG_ON(count < 1);
9748
9749         rx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9750         if (!rx)
9751                 return -ENOMEM;
9752
9753         dev->_rx = rx;
9754
9755         for (i = 0; i < count; i++) {
9756                 rx[i].dev = dev;
9757
9758                 /* XDP RX-queue setup */
9759                 err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i, 0);
9760                 if (err < 0)
9761                         goto err_rxq_info;
9762         }
9763         return 0;
9764
9765 err_rxq_info:
9766         /* Rollback successful reg's and free other resources */
9767         while (i--)
9768                 xdp_rxq_info_unreg(&rx[i].xdp_rxq);
9769         kvfree(dev->_rx);
9770         dev->_rx = NULL;
9771         return err;
9772 }
9773
9774 static void netif_free_rx_queues(struct net_device *dev)
9775 {
9776         unsigned int i, count = dev->num_rx_queues;
9777
9778         /* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
9779         if (!dev->_rx)
9780                 return;
9781
9782         for (i = 0; i < count; i++)
9783                 xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
9784
9785         kvfree(dev->_rx);
9786 }
9787
9788 static void netdev_init_one_queue(struct net_device *dev,
9789                                   struct netdev_queue *queue, void *_unused)
9790 {
9791         /* Initialize queue lock */
9792         spin_lock_init(&queue->_xmit_lock);
9793         netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
9794         queue->xmit_lock_owner = -1;
9795         netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
9796         queue->dev = dev;
9797 #ifdef CONFIG_BQL
9798         dql_init(&queue->dql, HZ);
9799 #endif
9800 }
9801
9802 static void netif_free_tx_queues(struct net_device *dev)
9803 {
9804         kvfree(dev->_tx);
9805 }
9806
9807 static int netif_alloc_netdev_queues(struct net_device *dev)
9808 {
9809         unsigned int count = dev->num_tx_queues;
9810         struct netdev_queue *tx;
9811         size_t sz = count * sizeof(*tx);
9812
9813         if (count < 1 || count > 0xffff)
9814                 return -EINVAL;
9815
9816         tx = kvzalloc(sz, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
9817         if (!tx)
9818                 return -ENOMEM;
9819
9820         dev->_tx = tx;
9821
9822         netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
9823         spin_lock_init(&dev->tx_global_lock);
9824
9825         return 0;
9826 }
9827
9828 void netif_tx_stop_all_queues(struct net_device *dev)
9829 {
9830         unsigned int i;
9831
9832         for (i = 0; i < dev->num_tx_queues; i++) {
9833                 struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
9834
9835                 netif_tx_stop_queue(txq);
9836         }
9837 }
9838 EXPORT_SYMBOL(netif_tx_stop_all_queues);
9839
9840 /**
9841  *      register_netdevice      - register a network device
9842  *      @dev: device to register
9843  *
9844  *      Take a completed network device structure and add it to the kernel
9845  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
9846  *      chain. 0 is returned on success. A negative errno code is returned
9847  *      on a failure to set up the device, or if the name is a duplicate.
9848  *
9849  *      Callers must hold the rtnl semaphore. You may want
9850  *      register_netdev() instead of this.
9851  *
9852  *      BUGS:
9853  *      The locking appears insufficient to guarantee two parallel registers
9854  *      will not get the same name.
9855  */
9856
9857 int register_netdevice(struct net_device *dev)
9858 {
9859         int ret;
9860         struct net *net = dev_net(dev);
9861
9862         BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
9863                      NETDEV_FEATURE_COUNT);
9864         BUG_ON(dev_boot_phase);
9865         ASSERT_RTNL();
9866
9867         might_sleep();
9868
9869         /* When net_device's are persistent, this will be fatal. */
9870         BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
9871         BUG_ON(!net);
9872
9873         ret = ethtool_check_ops(dev->ethtool_ops);
9874         if (ret)
9875                 return ret;
9876
9877         spin_lock_init(&dev->addr_list_lock);
9878         netdev_set_addr_lockdep_class(dev);
9879
9880         ret = dev_get_valid_name(net, dev, dev->name);
9881         if (ret < 0)
9882                 goto out;
9883
9884         ret = -ENOMEM;
9885         dev->name_node = netdev_name_node_head_alloc(dev);
9886         if (!dev->name_node)
9887                 goto out;
9888
9889         /* Init, if this function is available */
9890         if (dev->netdev_ops->ndo_init) {
9891                 ret = dev->netdev_ops->ndo_init(dev);
9892                 if (ret) {
9893                         if (ret > 0)
9894                                 ret = -EIO;
9895                         goto err_free_name;
9896                 }
9897         }
9898
9899         if (((dev->hw_features | dev->features) &
9900              NETIF_F_HW_VLAN_CTAG_FILTER) &&
9901             (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
9902              !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
9903                 netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
9904                 ret = -EINVAL;
9905                 goto err_uninit;
9906         }
9907
9908         ret = -EBUSY;
9909         if (!dev->ifindex)
9910                 dev->ifindex = dev_new_index(net);
9911         else if (__dev_get_by_index(net, dev->ifindex))
9912                 goto err_uninit;
9913
9914         /* Transfer changeable features to wanted_features and enable
9915          * software offloads (GSO and GRO).
9916          */
9917         dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
9918         dev->features |= NETIF_F_SOFT_FEATURES;
9919
9920         if (dev->udp_tunnel_nic_info) {
9921                 dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
9922                 dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
9923         }
9924
9925         dev->wanted_features = dev->features & dev->hw_features;
9926
9927         if (!(dev->flags & IFF_LOOPBACK))
9928                 dev->hw_features |= NETIF_F_NOCACHE_COPY;
9929
9930         /* If IPv4 TCP segmentation offload is supported we should also
9931          * allow the device to enable segmenting the frame with the option
9932          * of ignoring a static IP ID value.  This doesn't enable the
9933          * feature itself but allows the user to enable it later.
9934          */
9935         if (dev->hw_features & NETIF_F_TSO)
9936                 dev->hw_features |= NETIF_F_TSO_MANGLEID;
9937         if (dev->vlan_features & NETIF_F_TSO)
9938                 dev->vlan_features |= NETIF_F_TSO_MANGLEID;
9939         if (dev->mpls_features & NETIF_F_TSO)
9940                 dev->mpls_features |= NETIF_F_TSO_MANGLEID;
9941         if (dev->hw_enc_features & NETIF_F_TSO)
9942                 dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
9943
9944         /* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
9945          */
9946         dev->vlan_features |= NETIF_F_HIGHDMA;
9947
9948         /* Make NETIF_F_SG inheritable to tunnel devices.
9949          */
9950         dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
9951
9952         /* Make NETIF_F_SG inheritable to MPLS.
9953          */
9954         dev->mpls_features |= NETIF_F_SG;
9955
9956         ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
9957         ret = notifier_to_errno(ret);
9958         if (ret)
9959                 goto err_uninit;
9960
9961         ret = netdev_register_kobject(dev);
9962         if (ret) {
9963                 dev->reg_state = NETREG_UNREGISTERED;
9964                 goto err_uninit;
9965         }
9966         dev->reg_state = NETREG_REGISTERED;
9967
9968         __netdev_update_features(dev);
9969
9970         /*
9971          *      Default initial state at registry is that the
9972          *      device is present.
9973          */
9974
9975         set_bit(__LINK_STATE_PRESENT, &dev->state);
9976
9977         linkwatch_init_dev(dev);
9978
9979         dev_init_scheduler(dev);
9980
9981         dev_hold_track(dev, &dev->dev_registered_tracker, GFP_KERNEL);
9982         list_netdevice(dev);
9983
9984         add_device_randomness(dev->dev_addr, dev->addr_len);
9985
9986         /* If the device has permanent device address, driver should
9987          * set dev_addr and also addr_assign_type should be set to
9988          * NET_ADDR_PERM (default value).
9989          */
9990         if (dev->addr_assign_type == NET_ADDR_PERM)
9991                 memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
9992
9993         /* Notify protocols, that a new device appeared. */
9994         ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
9995         ret = notifier_to_errno(ret);
9996         if (ret) {
9997                 /* Expect explicit free_netdev() on failure */
9998                 dev->needs_free_netdev = false;
9999                 unregister_netdevice_queue(dev, NULL);
10000                 goto out;
10001         }
10002         /*
10003          *      Prevent userspace races by waiting until the network
10004          *      device is fully setup before sending notifications.
10005          */
10006         if (!dev->rtnl_link_ops ||
10007             dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10008                 rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
10009
10010 out:
10011         return ret;
10012
10013 err_uninit:
10014         if (dev->netdev_ops->ndo_uninit)
10015                 dev->netdev_ops->ndo_uninit(dev);
10016         if (dev->priv_destructor)
10017                 dev->priv_destructor(dev);
10018 err_free_name:
10019         netdev_name_node_free(dev->name_node);
10020         goto out;
10021 }
10022 EXPORT_SYMBOL(register_netdevice);
10023
10024 /**
10025  *      init_dummy_netdev       - init a dummy network device for NAPI
10026  *      @dev: device to init
10027  *
10028  *      This takes a network device structure and initialize the minimum
10029  *      amount of fields so it can be used to schedule NAPI polls without
10030  *      registering a full blown interface. This is to be used by drivers
10031  *      that need to tie several hardware interfaces to a single NAPI
10032  *      poll scheduler due to HW limitations.
10033  */
10034 int init_dummy_netdev(struct net_device *dev)
10035 {
10036         /* Clear everything. Note we don't initialize spinlocks
10037          * are they aren't supposed to be taken by any of the
10038          * NAPI code and this dummy netdev is supposed to be
10039          * only ever used for NAPI polls
10040          */
10041         memset(dev, 0, sizeof(struct net_device));
10042
10043         /* make sure we BUG if trying to hit standard
10044          * register/unregister code path
10045          */
10046         dev->reg_state = NETREG_DUMMY;
10047
10048         /* NAPI wants this */
10049         INIT_LIST_HEAD(&dev->napi_list);
10050
10051         /* a dummy interface is started by default */
10052         set_bit(__LINK_STATE_PRESENT, &dev->state);
10053         set_bit(__LINK_STATE_START, &dev->state);
10054
10055         /* napi_busy_loop stats accounting wants this */
10056         dev_net_set(dev, &init_net);
10057
10058         /* Note : We dont allocate pcpu_refcnt for dummy devices,
10059          * because users of this 'device' dont need to change
10060          * its refcount.
10061          */
10062
10063         return 0;
10064 }
10065 EXPORT_SYMBOL_GPL(init_dummy_netdev);
10066
10067
10068 /**
10069  *      register_netdev - register a network device
10070  *      @dev: device to register
10071  *
10072  *      Take a completed network device structure and add it to the kernel
10073  *      interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
10074  *      chain. 0 is returned on success. A negative errno code is returned
10075  *      on a failure to set up the device, or if the name is a duplicate.
10076  *
10077  *      This is a wrapper around register_netdevice that takes the rtnl semaphore
10078  *      and expands the device name if you passed a format string to
10079  *      alloc_netdev.
10080  */
10081 int register_netdev(struct net_device *dev)
10082 {
10083         int err;
10084
10085         if (rtnl_lock_killable())
10086                 return -EINTR;
10087         err = register_netdevice(dev);
10088         rtnl_unlock();
10089         return err;
10090 }
10091 EXPORT_SYMBOL(register_netdev);
10092
10093 int netdev_refcnt_read(const struct net_device *dev)
10094 {
10095 #ifdef CONFIG_PCPU_DEV_REFCNT
10096         int i, refcnt = 0;
10097
10098         for_each_possible_cpu(i)
10099                 refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
10100         return refcnt;
10101 #else
10102         return refcount_read(&dev->dev_refcnt);
10103 #endif
10104 }
10105 EXPORT_SYMBOL(netdev_refcnt_read);
10106
10107 int netdev_unregister_timeout_secs __read_mostly = 10;
10108
10109 #define WAIT_REFS_MIN_MSECS 1
10110 #define WAIT_REFS_MAX_MSECS 250
10111 /**
10112  * netdev_wait_allrefs_any - wait until all references are gone.
10113  * @list: list of net_devices to wait on
10114  *
10115  * This is called when unregistering network devices.
10116  *
10117  * Any protocol or device that holds a reference should register
10118  * for netdevice notification, and cleanup and put back the
10119  * reference if they receive an UNREGISTER event.
10120  * We can get stuck here if buggy protocols don't correctly
10121  * call dev_put.
10122  */
10123 static struct net_device *netdev_wait_allrefs_any(struct list_head *list)
10124 {
10125         unsigned long rebroadcast_time, warning_time;
10126         struct net_device *dev;
10127         int wait = 0;
10128
10129         rebroadcast_time = warning_time = jiffies;
10130
10131         list_for_each_entry(dev, list, todo_list)
10132                 if (netdev_refcnt_read(dev) == 1)
10133                         return dev;
10134
10135         while (true) {
10136                 if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
10137                         rtnl_lock();
10138
10139                         /* Rebroadcast unregister notification */
10140                         list_for_each_entry(dev, list, todo_list)
10141                                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10142
10143                         __rtnl_unlock();
10144                         rcu_barrier();
10145                         rtnl_lock();
10146
10147                         list_for_each_entry(dev, list, todo_list)
10148                                 if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
10149                                              &dev->state)) {
10150                                         /* We must not have linkwatch events
10151                                          * pending on unregister. If this
10152                                          * happens, we simply run the queue
10153                                          * unscheduled, resulting in a noop
10154                                          * for this device.
10155                                          */
10156                                         linkwatch_run_queue();
10157                                         break;
10158                                 }
10159
10160                         __rtnl_unlock();
10161
10162                         rebroadcast_time = jiffies;
10163                 }
10164
10165                 if (!wait) {
10166                         rcu_barrier();
10167                         wait = WAIT_REFS_MIN_MSECS;
10168                 } else {
10169                         msleep(wait);
10170                         wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
10171                 }
10172
10173                 list_for_each_entry(dev, list, todo_list)
10174                         if (netdev_refcnt_read(dev) == 1)
10175                                 return dev;
10176
10177                 if (time_after(jiffies, warning_time +
10178                                netdev_unregister_timeout_secs * HZ)) {
10179                         list_for_each_entry(dev, list, todo_list) {
10180                                 pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
10181                                          dev->name, netdev_refcnt_read(dev));
10182                                 ref_tracker_dir_print(&dev->refcnt_tracker, 10);
10183                         }
10184
10185                         warning_time = jiffies;
10186                 }
10187         }
10188 }
10189
10190 /* The sequence is:
10191  *
10192  *      rtnl_lock();
10193  *      ...
10194  *      register_netdevice(x1);
10195  *      register_netdevice(x2);
10196  *      ...
10197  *      unregister_netdevice(y1);
10198  *      unregister_netdevice(y2);
10199  *      ...
10200  *      rtnl_unlock();
10201  *      free_netdev(y1);
10202  *      free_netdev(y2);
10203  *
10204  * We are invoked by rtnl_unlock().
10205  * This allows us to deal with problems:
10206  * 1) We can delete sysfs objects which invoke hotplug
10207  *    without deadlocking with linkwatch via keventd.
10208  * 2) Since we run with the RTNL semaphore not held, we can sleep
10209  *    safely in order to wait for the netdev refcnt to drop to zero.
10210  *
10211  * We must not return until all unregister events added during
10212  * the interval the lock was held have been completed.
10213  */
10214 void netdev_run_todo(void)
10215 {
10216         struct net_device *dev, *tmp;
10217         struct list_head list;
10218 #ifdef CONFIG_LOCKDEP
10219         struct list_head unlink_list;
10220
10221         list_replace_init(&net_unlink_list, &unlink_list);
10222
10223         while (!list_empty(&unlink_list)) {
10224                 struct net_device *dev = list_first_entry(&unlink_list,
10225                                                           struct net_device,
10226                                                           unlink_list);
10227                 list_del_init(&dev->unlink_list);
10228                 dev->nested_level = dev->lower_level - 1;
10229         }
10230 #endif
10231
10232         /* Snapshot list, allow later requests */
10233         list_replace_init(&net_todo_list, &list);
10234
10235         __rtnl_unlock();
10236
10237         /* Wait for rcu callbacks to finish before next phase */
10238         if (!list_empty(&list))
10239                 rcu_barrier();
10240
10241         list_for_each_entry_safe(dev, tmp, &list, todo_list) {
10242                 if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
10243                         netdev_WARN(dev, "run_todo but not unregistering\n");
10244                         list_del(&dev->todo_list);
10245                         continue;
10246                 }
10247
10248                 dev->reg_state = NETREG_UNREGISTERED;
10249                 linkwatch_forget_dev(dev);
10250         }
10251
10252         while (!list_empty(&list)) {
10253                 dev = netdev_wait_allrefs_any(&list);
10254                 list_del(&dev->todo_list);
10255
10256                 /* paranoia */
10257                 BUG_ON(netdev_refcnt_read(dev) != 1);
10258                 BUG_ON(!list_empty(&dev->ptype_all));
10259                 BUG_ON(!list_empty(&dev->ptype_specific));
10260                 WARN_ON(rcu_access_pointer(dev->ip_ptr));
10261                 WARN_ON(rcu_access_pointer(dev->ip6_ptr));
10262 #if IS_ENABLED(CONFIG_DECNET)
10263                 WARN_ON(dev->dn_ptr);
10264 #endif
10265                 if (dev->priv_destructor)
10266                         dev->priv_destructor(dev);
10267                 if (dev->needs_free_netdev)
10268                         free_netdev(dev);
10269
10270                 if (atomic_dec_and_test(&dev_net(dev)->dev_unreg_count))
10271                         wake_up(&netdev_unregistering_wq);
10272
10273                 /* Free network device */
10274                 kobject_put(&dev->dev.kobj);
10275         }
10276 }
10277
10278 /* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
10279  * all the same fields in the same order as net_device_stats, with only
10280  * the type differing, but rtnl_link_stats64 may have additional fields
10281  * at the end for newer counters.
10282  */
10283 void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
10284                              const struct net_device_stats *netdev_stats)
10285 {
10286 #if BITS_PER_LONG == 64
10287         BUILD_BUG_ON(sizeof(*stats64) < sizeof(*netdev_stats));
10288         memcpy(stats64, netdev_stats, sizeof(*netdev_stats));
10289         /* zero out counters that only exist in rtnl_link_stats64 */
10290         memset((char *)stats64 + sizeof(*netdev_stats), 0,
10291                sizeof(*stats64) - sizeof(*netdev_stats));
10292 #else
10293         size_t i, n = sizeof(*netdev_stats) / sizeof(unsigned long);
10294         const unsigned long *src = (const unsigned long *)netdev_stats;
10295         u64 *dst = (u64 *)stats64;
10296
10297         BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
10298         for (i = 0; i < n; i++)
10299                 dst[i] = src[i];
10300         /* zero out counters that only exist in rtnl_link_stats64 */
10301         memset((char *)stats64 + n * sizeof(u64), 0,
10302                sizeof(*stats64) - n * sizeof(u64));
10303 #endif
10304 }
10305 EXPORT_SYMBOL(netdev_stats_to_stats64);
10306
10307 struct net_device_core_stats __percpu *netdev_core_stats_alloc(struct net_device *dev)
10308 {
10309         struct net_device_core_stats __percpu *p;
10310
10311         p = alloc_percpu_gfp(struct net_device_core_stats,
10312                              GFP_ATOMIC | __GFP_NOWARN);
10313
10314         if (p && cmpxchg(&dev->core_stats, NULL, p))
10315                 free_percpu(p);
10316
10317         /* This READ_ONCE() pairs with the cmpxchg() above */
10318         return READ_ONCE(dev->core_stats);
10319 }
10320 EXPORT_SYMBOL(netdev_core_stats_alloc);
10321
10322 /**
10323  *      dev_get_stats   - get network device statistics
10324  *      @dev: device to get statistics from
10325  *      @storage: place to store stats
10326  *
10327  *      Get network statistics from device. Return @storage.
10328  *      The device driver may provide its own method by setting
10329  *      dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
10330  *      otherwise the internal statistics structure is used.
10331  */
10332 struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
10333                                         struct rtnl_link_stats64 *storage)
10334 {
10335         const struct net_device_ops *ops = dev->netdev_ops;
10336         const struct net_device_core_stats __percpu *p;
10337
10338         if (ops->ndo_get_stats64) {
10339                 memset(storage, 0, sizeof(*storage));
10340                 ops->ndo_get_stats64(dev, storage);
10341         } else if (ops->ndo_get_stats) {
10342                 netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
10343         } else {
10344                 netdev_stats_to_stats64(storage, &dev->stats);
10345         }
10346
10347         /* This READ_ONCE() pairs with the write in netdev_core_stats_alloc() */
10348         p = READ_ONCE(dev->core_stats);
10349         if (p) {
10350                 const struct net_device_core_stats *core_stats;
10351                 int i;
10352
10353                 for_each_possible_cpu(i) {
10354                         core_stats = per_cpu_ptr(p, i);
10355                         storage->rx_dropped += READ_ONCE(core_stats->rx_dropped);
10356                         storage->tx_dropped += READ_ONCE(core_stats->tx_dropped);
10357                         storage->rx_nohandler += READ_ONCE(core_stats->rx_nohandler);
10358                 }
10359         }
10360         return storage;
10361 }
10362 EXPORT_SYMBOL(dev_get_stats);
10363
10364 /**
10365  *      dev_fetch_sw_netstats - get per-cpu network device statistics
10366  *      @s: place to store stats
10367  *      @netstats: per-cpu network stats to read from
10368  *
10369  *      Read per-cpu network statistics and populate the related fields in @s.
10370  */
10371 void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
10372                            const struct pcpu_sw_netstats __percpu *netstats)
10373 {
10374         int cpu;
10375
10376         for_each_possible_cpu(cpu) {
10377                 const struct pcpu_sw_netstats *stats;
10378                 struct pcpu_sw_netstats tmp;
10379                 unsigned int start;
10380
10381                 stats = per_cpu_ptr(netstats, cpu);
10382                 do {
10383                         start = u64_stats_fetch_begin_irq(&stats->syncp);
10384                         tmp.rx_packets = stats->rx_packets;
10385                         tmp.rx_bytes   = stats->rx_bytes;
10386                         tmp.tx_packets = stats->tx_packets;
10387                         tmp.tx_bytes   = stats->tx_bytes;
10388                 } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
10389
10390                 s->rx_packets += tmp.rx_packets;
10391                 s->rx_bytes   += tmp.rx_bytes;
10392                 s->tx_packets += tmp.tx_packets;
10393                 s->tx_bytes   += tmp.tx_bytes;
10394         }
10395 }
10396 EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
10397
10398 /**
10399  *      dev_get_tstats64 - ndo_get_stats64 implementation
10400  *      @dev: device to get statistics from
10401  *      @s: place to store stats
10402  *
10403  *      Populate @s from dev->stats and dev->tstats. Can be used as
10404  *      ndo_get_stats64() callback.
10405  */
10406 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s)
10407 {
10408         netdev_stats_to_stats64(s, &dev->stats);
10409         dev_fetch_sw_netstats(s, dev->tstats);
10410 }
10411 EXPORT_SYMBOL_GPL(dev_get_tstats64);
10412
10413 struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
10414 {
10415         struct netdev_queue *queue = dev_ingress_queue(dev);
10416
10417 #ifdef CONFIG_NET_CLS_ACT
10418         if (queue)
10419                 return queue;
10420         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
10421         if (!queue)
10422                 return NULL;
10423         netdev_init_one_queue(dev, queue, NULL);
10424         RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
10425         queue->qdisc_sleeping = &noop_qdisc;
10426         rcu_assign_pointer(dev->ingress_queue, queue);
10427 #endif
10428         return queue;
10429 }
10430
10431 static const struct ethtool_ops default_ethtool_ops;
10432
10433 void netdev_set_default_ethtool_ops(struct net_device *dev,
10434                                     const struct ethtool_ops *ops)
10435 {
10436         if (dev->ethtool_ops == &default_ethtool_ops)
10437                 dev->ethtool_ops = ops;
10438 }
10439 EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
10440
10441 void netdev_freemem(struct net_device *dev)
10442 {
10443         char *addr = (char *)dev - dev->padded;
10444
10445         kvfree(addr);
10446 }
10447
10448 /**
10449  * alloc_netdev_mqs - allocate network device
10450  * @sizeof_priv: size of private data to allocate space for
10451  * @name: device name format string
10452  * @name_assign_type: origin of device name
10453  * @setup: callback to initialize device
10454  * @txqs: the number of TX subqueues to allocate
10455  * @rxqs: the number of RX subqueues to allocate
10456  *
10457  * Allocates a struct net_device with private data area for driver use
10458  * and performs basic initialization.  Also allocates subqueue structs
10459  * for each queue on the device.
10460  */
10461 struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
10462                 unsigned char name_assign_type,
10463                 void (*setup)(struct net_device *),
10464                 unsigned int txqs, unsigned int rxqs)
10465 {
10466         struct net_device *dev;
10467         unsigned int alloc_size;
10468         struct net_device *p;
10469
10470         BUG_ON(strlen(name) >= sizeof(dev->name));
10471
10472         if (txqs < 1) {
10473                 pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
10474                 return NULL;
10475         }
10476
10477         if (rxqs < 1) {
10478                 pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
10479                 return NULL;
10480         }
10481
10482         alloc_size = sizeof(struct net_device);
10483         if (sizeof_priv) {
10484                 /* ensure 32-byte alignment of private area */
10485                 alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
10486                 alloc_size += sizeof_priv;
10487         }
10488         /* ensure 32-byte alignment of whole construct */
10489         alloc_size += NETDEV_ALIGN - 1;
10490
10491         p = kvzalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
10492         if (!p)
10493                 return NULL;
10494
10495         dev = PTR_ALIGN(p, NETDEV_ALIGN);
10496         dev->padded = (char *)dev - (char *)p;
10497
10498         ref_tracker_dir_init(&dev->refcnt_tracker, 128);
10499 #ifdef CONFIG_PCPU_DEV_REFCNT
10500         dev->pcpu_refcnt = alloc_percpu(int);
10501         if (!dev->pcpu_refcnt)
10502                 goto free_dev;
10503         __dev_hold(dev);
10504 #else
10505         refcount_set(&dev->dev_refcnt, 1);
10506 #endif
10507
10508         if (dev_addr_init(dev))
10509                 goto free_pcpu;
10510
10511         dev_mc_init(dev);
10512         dev_uc_init(dev);
10513
10514         dev_net_set(dev, &init_net);
10515
10516         dev->gso_max_size = GSO_MAX_SIZE;
10517         dev->gso_max_segs = GSO_MAX_SEGS;
10518         dev->gro_max_size = GRO_MAX_SIZE;
10519         dev->upper_level = 1;
10520         dev->lower_level = 1;
10521 #ifdef CONFIG_LOCKDEP
10522         dev->nested_level = 0;
10523         INIT_LIST_HEAD(&dev->unlink_list);
10524 #endif
10525
10526         INIT_LIST_HEAD(&dev->napi_list);
10527         INIT_LIST_HEAD(&dev->unreg_list);
10528         INIT_LIST_HEAD(&dev->close_list);
10529         INIT_LIST_HEAD(&dev->link_watch_list);
10530         INIT_LIST_HEAD(&dev->adj_list.upper);
10531         INIT_LIST_HEAD(&dev->adj_list.lower);
10532         INIT_LIST_HEAD(&dev->ptype_all);
10533         INIT_LIST_HEAD(&dev->ptype_specific);
10534         INIT_LIST_HEAD(&dev->net_notifier_list);
10535 #ifdef CONFIG_NET_SCHED
10536         hash_init(dev->qdisc_hash);
10537 #endif
10538         dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
10539         setup(dev);
10540
10541         if (!dev->tx_queue_len) {
10542                 dev->priv_flags |= IFF_NO_QUEUE;
10543                 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
10544         }
10545
10546         dev->num_tx_queues = txqs;
10547         dev->real_num_tx_queues = txqs;
10548         if (netif_alloc_netdev_queues(dev))
10549                 goto free_all;
10550
10551         dev->num_rx_queues = rxqs;
10552         dev->real_num_rx_queues = rxqs;
10553         if (netif_alloc_rx_queues(dev))
10554                 goto free_all;
10555
10556         strcpy(dev->name, name);
10557         dev->name_assign_type = name_assign_type;
10558         dev->group = INIT_NETDEV_GROUP;
10559         if (!dev->ethtool_ops)
10560                 dev->ethtool_ops = &default_ethtool_ops;
10561
10562         nf_hook_netdev_init(dev);
10563
10564         return dev;
10565
10566 free_all:
10567         free_netdev(dev);
10568         return NULL;
10569
10570 free_pcpu:
10571 #ifdef CONFIG_PCPU_DEV_REFCNT
10572         free_percpu(dev->pcpu_refcnt);
10573 free_dev:
10574 #endif
10575         netdev_freemem(dev);
10576         return NULL;
10577 }
10578 EXPORT_SYMBOL(alloc_netdev_mqs);
10579
10580 /**
10581  * free_netdev - free network device
10582  * @dev: device
10583  *
10584  * This function does the last stage of destroying an allocated device
10585  * interface. The reference to the device object is released. If this
10586  * is the last reference then it will be freed.Must be called in process
10587  * context.
10588  */
10589 void free_netdev(struct net_device *dev)
10590 {
10591         struct napi_struct *p, *n;
10592
10593         might_sleep();
10594
10595         /* When called immediately after register_netdevice() failed the unwind
10596          * handling may still be dismantling the device. Handle that case by
10597          * deferring the free.
10598          */
10599         if (dev->reg_state == NETREG_UNREGISTERING) {
10600                 ASSERT_RTNL();
10601                 dev->needs_free_netdev = true;
10602                 return;
10603         }
10604
10605         netif_free_tx_queues(dev);
10606         netif_free_rx_queues(dev);
10607
10608         kfree(rcu_dereference_protected(dev->ingress_queue, 1));
10609
10610         /* Flush device addresses */
10611         dev_addr_flush(dev);
10612
10613         list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
10614                 netif_napi_del(p);
10615
10616         ref_tracker_dir_exit(&dev->refcnt_tracker);
10617 #ifdef CONFIG_PCPU_DEV_REFCNT
10618         free_percpu(dev->pcpu_refcnt);
10619         dev->pcpu_refcnt = NULL;
10620 #endif
10621         free_percpu(dev->core_stats);
10622         dev->core_stats = NULL;
10623         free_percpu(dev->xdp_bulkq);
10624         dev->xdp_bulkq = NULL;
10625
10626         /*  Compatibility with error handling in drivers */
10627         if (dev->reg_state == NETREG_UNINITIALIZED) {
10628                 netdev_freemem(dev);
10629                 return;
10630         }
10631
10632         BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
10633         dev->reg_state = NETREG_RELEASED;
10634
10635         /* will free via device release */
10636         put_device(&dev->dev);
10637 }
10638 EXPORT_SYMBOL(free_netdev);
10639
10640 /**
10641  *      synchronize_net -  Synchronize with packet receive processing
10642  *
10643  *      Wait for packets currently being received to be done.
10644  *      Does not block later packets from starting.
10645  */
10646 void synchronize_net(void)
10647 {
10648         might_sleep();
10649         if (rtnl_is_locked())
10650                 synchronize_rcu_expedited();
10651         else
10652                 synchronize_rcu();
10653 }
10654 EXPORT_SYMBOL(synchronize_net);
10655
10656 /**
10657  *      unregister_netdevice_queue - remove device from the kernel
10658  *      @dev: device
10659  *      @head: list
10660  *
10661  *      This function shuts down a device interface and removes it
10662  *      from the kernel tables.
10663  *      If head not NULL, device is queued to be unregistered later.
10664  *
10665  *      Callers must hold the rtnl semaphore.  You may want
10666  *      unregister_netdev() instead of this.
10667  */
10668
10669 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
10670 {
10671         ASSERT_RTNL();
10672
10673         if (head) {
10674                 list_move_tail(&dev->unreg_list, head);
10675         } else {
10676                 LIST_HEAD(single);
10677
10678                 list_add(&dev->unreg_list, &single);
10679                 unregister_netdevice_many(&single);
10680         }
10681 }
10682 EXPORT_SYMBOL(unregister_netdevice_queue);
10683
10684 /**
10685  *      unregister_netdevice_many - unregister many devices
10686  *      @head: list of devices
10687  *
10688  *  Note: As most callers use a stack allocated list_head,
10689  *  we force a list_del() to make sure stack wont be corrupted later.
10690  */
10691 void unregister_netdevice_many(struct list_head *head)
10692 {
10693         struct net_device *dev, *tmp;
10694         LIST_HEAD(close_head);
10695
10696         BUG_ON(dev_boot_phase);
10697         ASSERT_RTNL();
10698
10699         if (list_empty(head))
10700                 return;
10701
10702         list_for_each_entry_safe(dev, tmp, head, unreg_list) {
10703                 /* Some devices call without registering
10704                  * for initialization unwind. Remove those
10705                  * devices and proceed with the remaining.
10706                  */
10707                 if (dev->reg_state == NETREG_UNINITIALIZED) {
10708                         pr_debug("unregister_netdevice: device %s/%p never was registered\n",
10709                                  dev->name, dev);
10710
10711                         WARN_ON(1);
10712                         list_del(&dev->unreg_list);
10713                         continue;
10714                 }
10715                 dev->dismantle = true;
10716                 BUG_ON(dev->reg_state != NETREG_REGISTERED);
10717         }
10718
10719         /* If device is running, close it first. */
10720         list_for_each_entry(dev, head, unreg_list)
10721                 list_add_tail(&dev->close_list, &close_head);
10722         dev_close_many(&close_head, true);
10723
10724         list_for_each_entry(dev, head, unreg_list) {
10725                 /* And unlink it from device chain. */
10726                 unlist_netdevice(dev);
10727
10728                 dev->reg_state = NETREG_UNREGISTERING;
10729         }
10730         flush_all_backlogs();
10731
10732         synchronize_net();
10733
10734         list_for_each_entry(dev, head, unreg_list) {
10735                 struct sk_buff *skb = NULL;
10736
10737                 /* Shutdown queueing discipline. */
10738                 dev_shutdown(dev);
10739
10740                 dev_xdp_uninstall(dev);
10741
10742                 netdev_offload_xstats_disable_all(dev);
10743
10744                 /* Notify protocols, that we are about to destroy
10745                  * this device. They should clean all the things.
10746                  */
10747                 call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10748
10749                 if (!dev->rtnl_link_ops ||
10750                     dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
10751                         skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
10752                                                      GFP_KERNEL, NULL, 0);
10753
10754                 /*
10755                  *      Flush the unicast and multicast chains
10756                  */
10757                 dev_uc_flush(dev);
10758                 dev_mc_flush(dev);
10759
10760                 netdev_name_node_alt_flush(dev);
10761                 netdev_name_node_free(dev->name_node);
10762
10763                 if (dev->netdev_ops->ndo_uninit)
10764                         dev->netdev_ops->ndo_uninit(dev);
10765
10766                 if (skb)
10767                         rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
10768
10769                 /* Notifier chain MUST detach us all upper devices. */
10770                 WARN_ON(netdev_has_any_upper_dev(dev));
10771                 WARN_ON(netdev_has_any_lower_dev(dev));
10772
10773                 /* Remove entries from kobject tree */
10774                 netdev_unregister_kobject(dev);
10775 #ifdef CONFIG_XPS
10776                 /* Remove XPS queueing entries */
10777                 netif_reset_xps_queues_gt(dev, 0);
10778 #endif
10779         }
10780
10781         synchronize_net();
10782
10783         list_for_each_entry(dev, head, unreg_list) {
10784                 dev_put_track(dev, &dev->dev_registered_tracker);
10785                 net_set_todo(dev);
10786         }
10787
10788         list_del(head);
10789 }
10790 EXPORT_SYMBOL(unregister_netdevice_many);
10791
10792 /**
10793  *      unregister_netdev - remove device from the kernel
10794  *      @dev: device
10795  *
10796  *      This function shuts down a device interface and removes it
10797  *      from the kernel tables.
10798  *
10799  *      This is just a wrapper for unregister_netdevice that takes
10800  *      the rtnl semaphore.  In general you want to use this and not
10801  *      unregister_netdevice.
10802  */
10803 void unregister_netdev(struct net_device *dev)
10804 {
10805         rtnl_lock();
10806         unregister_netdevice(dev);
10807         rtnl_unlock();
10808 }
10809 EXPORT_SYMBOL(unregister_netdev);
10810
10811 /**
10812  *      __dev_change_net_namespace - move device to different nethost namespace
10813  *      @dev: device
10814  *      @net: network namespace
10815  *      @pat: If not NULL name pattern to try if the current device name
10816  *            is already taken in the destination network namespace.
10817  *      @new_ifindex: If not zero, specifies device index in the target
10818  *                    namespace.
10819  *
10820  *      This function shuts down a device interface and moves it
10821  *      to a new network namespace. On success 0 is returned, on
10822  *      a failure a netagive errno code is returned.
10823  *
10824  *      Callers must hold the rtnl semaphore.
10825  */
10826
10827 int __dev_change_net_namespace(struct net_device *dev, struct net *net,
10828                                const char *pat, int new_ifindex)
10829 {
10830         struct net *net_old = dev_net(dev);
10831         int err, new_nsid;
10832
10833         ASSERT_RTNL();
10834
10835         /* Don't allow namespace local devices to be moved. */
10836         err = -EINVAL;
10837         if (dev->features & NETIF_F_NETNS_LOCAL)
10838                 goto out;
10839
10840         /* Ensure the device has been registrered */
10841         if (dev->reg_state != NETREG_REGISTERED)
10842                 goto out;
10843
10844         /* Get out if there is nothing todo */
10845         err = 0;
10846         if (net_eq(net_old, net))
10847                 goto out;
10848
10849         /* Pick the destination device name, and ensure
10850          * we can use it in the destination network namespace.
10851          */
10852         err = -EEXIST;
10853         if (netdev_name_in_use(net, dev->name)) {
10854                 /* We get here if we can't use the current device name */
10855                 if (!pat)
10856                         goto out;
10857                 err = dev_get_valid_name(net, dev, pat);
10858                 if (err < 0)
10859                         goto out;
10860         }
10861
10862         /* Check that new_ifindex isn't used yet. */
10863         err = -EBUSY;
10864         if (new_ifindex && __dev_get_by_index(net, new_ifindex))
10865                 goto out;
10866
10867         /*
10868          * And now a mini version of register_netdevice unregister_netdevice.
10869          */
10870
10871         /* If device is running close it first. */
10872         dev_close(dev);
10873
10874         /* And unlink it from device chain */
10875         unlist_netdevice(dev);
10876
10877         synchronize_net();
10878
10879         /* Shutdown queueing discipline. */
10880         dev_shutdown(dev);
10881
10882         /* Notify protocols, that we are about to destroy
10883          * this device. They should clean all the things.
10884          *
10885          * Note that dev->reg_state stays at NETREG_REGISTERED.
10886          * This is wanted because this way 8021q and macvlan know
10887          * the device is just moving and can keep their slaves up.
10888          */
10889         call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
10890         rcu_barrier();
10891
10892         new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
10893         /* If there is an ifindex conflict assign a new one */
10894         if (!new_ifindex) {
10895                 if (__dev_get_by_index(net, dev->ifindex))
10896                         new_ifindex = dev_new_index(net);
10897                 else
10898                         new_ifindex = dev->ifindex;
10899         }
10900
10901         rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
10902                             new_ifindex);
10903
10904         /*
10905          *      Flush the unicast and multicast chains
10906          */
10907         dev_uc_flush(dev);
10908         dev_mc_flush(dev);
10909
10910         /* Send a netdev-removed uevent to the old namespace */
10911         kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
10912         netdev_adjacent_del_links(dev);
10913
10914         /* Move per-net netdevice notifiers that are following the netdevice */
10915         move_netdevice_notifiers_dev_net(dev, net);
10916
10917         /* Actually switch the network namespace */
10918         dev_net_set(dev, net);
10919         dev->ifindex = new_ifindex;
10920
10921         /* Send a netdev-add uevent to the new namespace */
10922         kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
10923         netdev_adjacent_add_links(dev);
10924
10925         /* Fixup kobjects */
10926         err = device_rename(&dev->dev, dev->name);
10927         WARN_ON(err);
10928
10929         /* Adapt owner in case owning user namespace of target network
10930          * namespace is different from the original one.
10931          */
10932         err = netdev_change_owner(dev, net_old, net);
10933         WARN_ON(err);
10934
10935         /* Add the device back in the hashes */
10936         list_netdevice(dev);
10937
10938         /* Notify protocols, that a new device appeared. */
10939         call_netdevice_notifiers(NETDEV_REGISTER, dev);
10940
10941         /*
10942          *      Prevent userspace races by waiting until the network
10943          *      device is fully setup before sending notifications.
10944          */
10945         rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
10946
10947         synchronize_net();
10948         err = 0;
10949 out:
10950         return err;
10951 }
10952 EXPORT_SYMBOL_GPL(__dev_change_net_namespace);
10953
10954 static int dev_cpu_dead(unsigned int oldcpu)
10955 {
10956         struct sk_buff **list_skb;
10957         struct sk_buff *skb;
10958         unsigned int cpu;
10959         struct softnet_data *sd, *oldsd, *remsd = NULL;
10960
10961         local_irq_disable();
10962         cpu = smp_processor_id();
10963         sd = &per_cpu(softnet_data, cpu);
10964         oldsd = &per_cpu(softnet_data, oldcpu);
10965
10966         /* Find end of our completion_queue. */
10967         list_skb = &sd->completion_queue;
10968         while (*list_skb)
10969                 list_skb = &(*list_skb)->next;
10970         /* Append completion queue from offline CPU. */
10971         *list_skb = oldsd->completion_queue;
10972         oldsd->completion_queue = NULL;
10973
10974         /* Append output queue from offline CPU. */
10975         if (oldsd->output_queue) {
10976                 *sd->output_queue_tailp = oldsd->output_queue;
10977                 sd->output_queue_tailp = oldsd->output_queue_tailp;
10978                 oldsd->output_queue = NULL;
10979                 oldsd->output_queue_tailp = &oldsd->output_queue;
10980         }
10981         /* Append NAPI poll list from offline CPU, with one exception :
10982          * process_backlog() must be called by cpu owning percpu backlog.
10983          * We properly handle process_queue & input_pkt_queue later.
10984          */
10985         while (!list_empty(&oldsd->poll_list)) {
10986                 struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
10987                                                             struct napi_struct,
10988                                                             poll_list);
10989
10990                 list_del_init(&napi->poll_list);
10991                 if (napi->poll == process_backlog)
10992                         napi->state = 0;
10993                 else
10994                         ____napi_schedule(sd, napi);
10995         }
10996
10997         raise_softirq_irqoff(NET_TX_SOFTIRQ);
10998         local_irq_enable();
10999
11000 #ifdef CONFIG_RPS
11001         remsd = oldsd->rps_ipi_list;
11002         oldsd->rps_ipi_list = NULL;
11003 #endif
11004         /* send out pending IPI's on offline CPU */
11005         net_rps_send_ipi(remsd);
11006
11007         /* Process offline CPU's input_pkt_queue */
11008         while ((skb = __skb_dequeue(&oldsd->process_queue))) {
11009                 netif_rx(skb);
11010                 input_queue_head_incr(oldsd);
11011         }
11012         while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
11013                 netif_rx(skb);
11014                 input_queue_head_incr(oldsd);
11015         }
11016
11017         return 0;
11018 }
11019
11020 /**
11021  *      netdev_increment_features - increment feature set by one
11022  *      @all: current feature set
11023  *      @one: new feature set
11024  *      @mask: mask feature set
11025  *
11026  *      Computes a new feature set after adding a device with feature set
11027  *      @one to the master device with current feature set @all.  Will not
11028  *      enable anything that is off in @mask. Returns the new feature set.
11029  */
11030 netdev_features_t netdev_increment_features(netdev_features_t all,
11031         netdev_features_t one, netdev_features_t mask)
11032 {
11033         if (mask & NETIF_F_HW_CSUM)
11034                 mask |= NETIF_F_CSUM_MASK;
11035         mask |= NETIF_F_VLAN_CHALLENGED;
11036
11037         all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
11038         all &= one | ~NETIF_F_ALL_FOR_ALL;
11039
11040         /* If one device supports hw checksumming, set for all. */
11041         if (all & NETIF_F_HW_CSUM)
11042                 all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
11043
11044         return all;
11045 }
11046 EXPORT_SYMBOL(netdev_increment_features);
11047
11048 static struct hlist_head * __net_init netdev_create_hash(void)
11049 {
11050         int i;
11051         struct hlist_head *hash;
11052
11053         hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
11054         if (hash != NULL)
11055                 for (i = 0; i < NETDEV_HASHENTRIES; i++)
11056                         INIT_HLIST_HEAD(&hash[i]);
11057
11058         return hash;
11059 }
11060
11061 /* Initialize per network namespace state */
11062 static int __net_init netdev_init(struct net *net)
11063 {
11064         BUILD_BUG_ON(GRO_HASH_BUCKETS >
11065                      8 * sizeof_field(struct napi_struct, gro_bitmask));
11066
11067         INIT_LIST_HEAD(&net->dev_base_head);
11068
11069         net->dev_name_head = netdev_create_hash();
11070         if (net->dev_name_head == NULL)
11071                 goto err_name;
11072
11073         net->dev_index_head = netdev_create_hash();
11074         if (net->dev_index_head == NULL)
11075                 goto err_idx;
11076
11077         RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
11078
11079         return 0;
11080
11081 err_idx:
11082         kfree(net->dev_name_head);
11083 err_name:
11084         return -ENOMEM;
11085 }
11086
11087 /**
11088  *      netdev_drivername - network driver for the device
11089  *      @dev: network device
11090  *
11091  *      Determine network driver for device.
11092  */
11093 const char *netdev_drivername(const struct net_device *dev)
11094 {
11095         const struct device_driver *driver;
11096         const struct device *parent;
11097         const char *empty = "";
11098
11099         parent = dev->dev.parent;
11100         if (!parent)
11101                 return empty;
11102
11103         driver = parent->driver;
11104         if (driver && driver->name)
11105                 return driver->name;
11106         return empty;
11107 }
11108
11109 static void __netdev_printk(const char *level, const struct net_device *dev,
11110                             struct va_format *vaf)
11111 {
11112         if (dev && dev->dev.parent) {
11113                 dev_printk_emit(level[1] - '0',
11114                                 dev->dev.parent,
11115                                 "%s %s %s%s: %pV",
11116                                 dev_driver_string(dev->dev.parent),
11117                                 dev_name(dev->dev.parent),
11118                                 netdev_name(dev), netdev_reg_state(dev),
11119                                 vaf);
11120         } else if (dev) {
11121                 printk("%s%s%s: %pV",
11122                        level, netdev_name(dev), netdev_reg_state(dev), vaf);
11123         } else {
11124                 printk("%s(NULL net_device): %pV", level, vaf);
11125         }
11126 }
11127
11128 void netdev_printk(const char *level, const struct net_device *dev,
11129                    const char *format, ...)
11130 {
11131         struct va_format vaf;
11132         va_list args;
11133
11134         va_start(args, format);
11135
11136         vaf.fmt = format;
11137         vaf.va = &args;
11138
11139         __netdev_printk(level, dev, &vaf);
11140
11141         va_end(args);
11142 }
11143 EXPORT_SYMBOL(netdev_printk);
11144
11145 #define define_netdev_printk_level(func, level)                 \
11146 void func(const struct net_device *dev, const char *fmt, ...)   \
11147 {                                                               \
11148         struct va_format vaf;                                   \
11149         va_list args;                                           \
11150                                                                 \
11151         va_start(args, fmt);                                    \
11152                                                                 \
11153         vaf.fmt = fmt;                                          \
11154         vaf.va = &args;                                         \
11155                                                                 \
11156         __netdev_printk(level, dev, &vaf);                      \
11157                                                                 \
11158         va_end(args);                                           \
11159 }                                                               \
11160 EXPORT_SYMBOL(func);
11161
11162 define_netdev_printk_level(netdev_emerg, KERN_EMERG);
11163 define_netdev_printk_level(netdev_alert, KERN_ALERT);
11164 define_netdev_printk_level(netdev_crit, KERN_CRIT);
11165 define_netdev_printk_level(netdev_err, KERN_ERR);
11166 define_netdev_printk_level(netdev_warn, KERN_WARNING);
11167 define_netdev_printk_level(netdev_notice, KERN_NOTICE);
11168 define_netdev_printk_level(netdev_info, KERN_INFO);
11169
11170 static void __net_exit netdev_exit(struct net *net)
11171 {
11172         kfree(net->dev_name_head);
11173         kfree(net->dev_index_head);
11174         if (net != &init_net)
11175                 WARN_ON_ONCE(!list_empty(&net->dev_base_head));
11176 }
11177
11178 static struct pernet_operations __net_initdata netdev_net_ops = {
11179         .init = netdev_init,
11180         .exit = netdev_exit,
11181 };
11182
11183 static void __net_exit default_device_exit_net(struct net *net)
11184 {
11185         struct net_device *dev, *aux;
11186         /*
11187          * Push all migratable network devices back to the
11188          * initial network namespace
11189          */
11190         ASSERT_RTNL();
11191         for_each_netdev_safe(net, dev, aux) {
11192                 int err;
11193                 char fb_name[IFNAMSIZ];
11194
11195                 /* Ignore unmoveable devices (i.e. loopback) */
11196                 if (dev->features & NETIF_F_NETNS_LOCAL)
11197                         continue;
11198
11199                 /* Leave virtual devices for the generic cleanup */
11200                 if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
11201                         continue;
11202
11203                 /* Push remaining network devices to init_net */
11204                 snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
11205                 if (netdev_name_in_use(&init_net, fb_name))
11206                         snprintf(fb_name, IFNAMSIZ, "dev%%d");
11207                 err = dev_change_net_namespace(dev, &init_net, fb_name);
11208                 if (err) {
11209                         pr_emerg("%s: failed to move %s to init_net: %d\n",
11210                                  __func__, dev->name, err);
11211                         BUG();
11212                 }
11213         }
11214 }
11215
11216 static void __net_exit default_device_exit_batch(struct list_head *net_list)
11217 {
11218         /* At exit all network devices most be removed from a network
11219          * namespace.  Do this in the reverse order of registration.
11220          * Do this across as many network namespaces as possible to
11221          * improve batching efficiency.
11222          */
11223         struct net_device *dev;
11224         struct net *net;
11225         LIST_HEAD(dev_kill_list);
11226
11227         rtnl_lock();
11228         list_for_each_entry(net, net_list, exit_list) {
11229                 default_device_exit_net(net);
11230                 cond_resched();
11231         }
11232
11233         list_for_each_entry(net, net_list, exit_list) {
11234                 for_each_netdev_reverse(net, dev) {
11235                         if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
11236                                 dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
11237                         else
11238                                 unregister_netdevice_queue(dev, &dev_kill_list);
11239                 }
11240         }
11241         unregister_netdevice_many(&dev_kill_list);
11242         rtnl_unlock();
11243 }
11244
11245 static struct pernet_operations __net_initdata default_device_ops = {
11246         .exit_batch = default_device_exit_batch,
11247 };
11248
11249 /*
11250  *      Initialize the DEV module. At boot time this walks the device list and
11251  *      unhooks any devices that fail to initialise (normally hardware not
11252  *      present) and leaves us with a valid list of present and active devices.
11253  *
11254  */
11255
11256 /*
11257  *       This is called single threaded during boot, so no need
11258  *       to take the rtnl semaphore.
11259  */
11260 static int __init net_dev_init(void)
11261 {
11262         int i, rc = -ENOMEM;
11263
11264         BUG_ON(!dev_boot_phase);
11265
11266         if (dev_proc_init())
11267                 goto out;
11268
11269         if (netdev_kobject_init())
11270                 goto out;
11271
11272         INIT_LIST_HEAD(&ptype_all);
11273         for (i = 0; i < PTYPE_HASH_SIZE; i++)
11274                 INIT_LIST_HEAD(&ptype_base[i]);
11275
11276         if (register_pernet_subsys(&netdev_net_ops))
11277                 goto out;
11278
11279         /*
11280          *      Initialise the packet receive queues.
11281          */
11282
11283         for_each_possible_cpu(i) {
11284                 struct work_struct *flush = per_cpu_ptr(&flush_works, i);
11285                 struct softnet_data *sd = &per_cpu(softnet_data, i);
11286
11287                 INIT_WORK(flush, flush_backlog);
11288
11289                 skb_queue_head_init(&sd->input_pkt_queue);
11290                 skb_queue_head_init(&sd->process_queue);
11291 #ifdef CONFIG_XFRM_OFFLOAD
11292                 skb_queue_head_init(&sd->xfrm_backlog);
11293 #endif
11294                 INIT_LIST_HEAD(&sd->poll_list);
11295                 sd->output_queue_tailp = &sd->output_queue;
11296 #ifdef CONFIG_RPS
11297                 INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
11298                 sd->cpu = i;
11299 #endif
11300
11301                 init_gro_hash(&sd->backlog);
11302                 sd->backlog.poll = process_backlog;
11303                 sd->backlog.weight = weight_p;
11304         }
11305
11306         dev_boot_phase = 0;
11307
11308         /* The loopback device is special if any other network devices
11309          * is present in a network namespace the loopback device must
11310          * be present. Since we now dynamically allocate and free the
11311          * loopback device ensure this invariant is maintained by
11312          * keeping the loopback device as the first device on the
11313          * list of network devices.  Ensuring the loopback devices
11314          * is the first device that appears and the last network device
11315          * that disappears.
11316          */
11317         if (register_pernet_device(&loopback_net_ops))
11318                 goto out;
11319
11320         if (register_pernet_device(&default_device_ops))
11321                 goto out;
11322
11323         open_softirq(NET_TX_SOFTIRQ, net_tx_action);
11324         open_softirq(NET_RX_SOFTIRQ, net_rx_action);
11325
11326         rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
11327                                        NULL, dev_cpu_dead);
11328         WARN_ON(rc < 0);
11329         rc = 0;
11330 out:
11331         return rc;
11332 }
11333
11334 subsys_initcall(net_dev_init);